Dispensing (101-200 questions)

a. for the treatment of cough and asthma symptoms

Lagundi has been studied by the Philippine Department of Health and has suggested a number of therapeutic values. One of these is;

a. for the treatment of cough and asthma symptoms

b. as prophylaxis for migraine

c. for painful or difficult menstruation

d. as supportive treatment for anxiety and depression

b. easier to correct than prevent

The following statements are TRUE regarding incompatibilities in prescription EXCEPT:

a. problems arising during compounding, dispensing and drug administration

b. easier to correct than prevent

c. may be intentional or unintentional

d. must be recognized by the pharmacist

b. Liberation of SO2 , NO2 , and H2 S

Which of the following is considered as an incompatibility in prescription?

a. Release of CO2 in effervescent formulation

b. Liberation of SO2 , NO2 , and H2 S

c. Precipitates formed in washes and lotions

d. All of these

a. Salting-out

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Explanation:

• Salting-out happens when adding salts (like KBr) reduces the solubility of another substance (like camphor) in water, causing it to precipitate.

KBr + Camphor water may lead to precipitation. What mechanism is involved?

a. Salting-out

b. change in solvent system

c. change in temperature

d. change in pH

d. polymorphism

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• Eutexia, deliquescence, and hygroscopy all involve substances absorbing moisture from the air, causing liquefaction.

• Polymorphism refers to different crystal forms of the same substance and does not cause liquefaction.

Liquefaction in prescription could be due to the following EXCEPT;

a. eutexia

b. deliquescence

c. hygroscopy

d. polymorphism

d. Deliquescent

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• Deliquescent substances absorb so much moisture from the air that they dissolve in the water they absorb, forming a liquid solution.

• Hygroscopic substances also absorb moisture but usually don’t dissolve completely.

• Eutectic refers to mixtures that melt at lower temperatures, not moisture absorption.

• Endothermic relates to heat absorption, not moisture.

These substances have strong affinity for moisture and tend to absorb relatively large amounts of water from the atmosphere if exposed to it, forming a liquid solution.

a. Endothermic

b. Eutectic

c. Hygroscopic

d. Deliquescent

a. Precipitation due to chemical reaction

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Silver nitrate reacts with sodium chloride to form silver chloride, which is insoluble and precipitates out.

Rx Silver Nitrate, Water. Make isotonic with Sodium Chloride. What incompatibility could be predicted from this combination?

a. Precipitation due to chemical reaction

b. Inactivation of Silver chloride via hydrolysis

c. Evolution of gas

d. Solidification

c. II and III

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• Syrup of Ipecac and Syrup of Orange contain acids (like citric acid) that react with carbonates or bicarbonates to release carbon dioxide gas.

• Syrup, USP is usually neutral and does not cause this reaction.

Liberation of carbon dioxide occurs when acid preparations are combined with carbonates or bicarbonates. Which of the following syrups is incompatible with carbonates and bicarbonates?

I. Syrup, USP

II. Syrup of Ipecac

III. Syrup of Orange

a. I, II and III

b. I and II

c. II and III

d. III only

c. II and III

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NOTE: Discoloration of Tablet= Oxidation

Hydrolysis of aspirin tablets can be manifested as;

I. Discoloration of the tablet

II. Vinegar-like odor of the tablet

III. Needle like crystals noted around the tablet

a. I, II and III

b. I and II

c. II and III

d. I and III

d. I and II

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The brown quinoid derivative forms due to oxidation of sodium salicylate in the presence of water.

• Adding an antioxidant (II) helps stop the oxidation.

• Adding a color diluent (I) can mask or dilute the brown color, making it less noticeable.

In the prescription, Sodium bicarbonate, Sodium salicylate, and Water qs., a brown quinoid derivative of sodium salicylate may be formed. This incompatibility can be remedied by:

I. Adding a color diluent

II. Adding an antioxidant

III. Removal of water

a. I, II and III

b. II and III

c. I and III

d. I and II

b. I and II

Possible remedies for liquefaction of solid substances include;

I. Dispense separately

II. Add adsorbents

III. Add cotton in packaging

a. I and III

b. I and II

c. II and III

d. I,II and III

a. I only

Alkaline salts like phenytoin sodium when placed in an acidic medium will result to:

I. precipitation of phenytoin into free acid

II. Inactivation of phenytoin sodium

III. Evolution of carbon dioxide gas

a. I only

b. II only

c. I and II

d. I, II, and III

c. I and III

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I. Addition of co-solvent — helps the solid dissolve better by changing the solvent properties.
III. Prepare a suspension — if the solid can’t dissolve, you can suspend tiny particles in the liquid.

II. Prepare an emulsion is for mixing two immiscible liquids, so it’s not useful here.

Remedy when a solid substance fails to dissolve in a liquid:

I. addition of co-solvent

II. prepare an emulsion

III. prepare a suspension

a. I and II

b. II and III

c. I and III

d. I, II, and III

d. I, II, and III

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• Chloral hydrate, phenol, and salicylic acid all form eutectic mixtures with camphor.

• A eutectic mixture is when substances melt at a lower temperature than their individual melting points, often resulting in a liquid or soft mass.

Which of the following substances or compounds would tend to form a liquid or soft mass when brought in contact with camphor?

I. chloral hydrate

II. phenol

III. salicylic acid

a. I and II

b. II and III

c. I and III

d. I, II, and III

b. chloramphenicol

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• Chloramphenicol can cause bone marrow suppression (aplastic anemia) and blocks bacterial protein synthesis.

• This makes its use risky and requires careful monitoring

Dispensing of this antibiotic should be watched carefully as it depresses the bone marrow and block protein synthesis.

a. bacitracin

b. chloramphenicol

c. penicillin

d. cefaclor

c. tinctures instead of fluidextracts

• underdose, less concentrated

Overdosage could be due to the following EXCEPT;

a. Excessive amounts taken at one time

b. Doses repeated at too frequent intervalsm

c. tinctures instead of fluidextracts

d. Dose dumping from modified-release formulation

d. epinephrine

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Epinephrine can oxidize to adrenochrome, which is brown and can stain contact lenses

Contact lenses will turn brown when prescribe to a patient who is also using this medication due to the formation of adrenochrome.

a. ibuprofen

b. propranolol

c. lidocaine

d. epinephrine

d. I, II and III

Tetracycline should not be taken with;

I. Dairy products

II. Antacid preparations

III. Hematinics

a. I and II

b. I and III

c. II and III

d. I, II and III

c. I and II

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I. NSAIDs and II. Thiazide diuretics both increase the risk of gastrointestinal ulcers and potassium loss when taken with corticosteroids.

When taking corticosteroids, patient should avoid;

I. NSAIDs

II. Thiazide diuretics

III. Insulin products

a. I, II and III

b. II and III

c. I and II

d. I only

a. understanding

In medication counseling, the basic goal is;

a. understanding

b. disagreement

c. to let the patient do as they are told

d. conflict

b. Repeat prescription counseling

Checking compliance and side effects are information gathered in;

a. New prescription counseling

b. Repeat prescription counseling

c. OTC counseling

d. all

a. I only

A medication history interview is conducted to;

I. new patient

II. returning patient

III. refill prescription

a. I only

b. II only

c. III only

d. I and II

a. I, II and III

Information to be provided in dispensing new prescription include;

I. refill information

II. side effects and adverse effects

III. purpose of the medication

a. I, II and III

b. II and III

c. I and III

d. I and II

b. effectiveness of medication

"Does your medication lower your high blood pressure?" This is a specific question about:

a. compliance

b. effectiveness of medication

c. previous use of medication

d. purpose of medication

d. I, II and III

Practical strategies to reduce errors resulting from sound-alike medications and verbal orders include:

I. read back verbal orders

II. prohibit the use of all verbal orders

III. establish policies on who can receive verbal orders

a. I and II

b. II and III

c. I and III

d. I, II and III

d. Flag shelves where the look-alike products are stored

One strategy to decrease dispensing errors associated with look-alike medications is to:

a. store problem medications alphabetically

b. use only generic names on labels

c. avoid incorporating alerts in computer systems

d. Flag shelves where the look-alike products are stored

b. can result in significant patient harm

Certain medications are deemed high-alert because they:

a. are more error prone

b. can result in significant patient harm

c. are labeled as such by FDA

d. a and c

c. concentrated electrolytes

JCAHO patient safety goals encourage hospitals to remove _______ from floor stock.

a. lidocaine

b. esmolol

c. concentrated electrolytes

d. all of these

Joint Commission on Accrediting Health Organization

JCAHO meaning is ___ ?

JCAHO

_____ - is the accrediting body of hospital pharmacy

c. Refrigerator

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• Temperatures between 1.5°C and 3.3°C are typical for a refrigerator.

  • Room temperature is usually around 20-25°C

  • freezer is below 0°C

  • incubator is warmer (around 37°C)

A new product has arrived to your pharmacy. The storage requirements on the label read: Store at 1.5°C - 3.3°C. Where would you store it?

a. Room temperature

b. Freezer

c. Refrigerator

d. Incubator

a. Look-alike and Sound-alike drugs

The use of "tall-man" letters in label avoids errors due to;

a. Look-alike and Sound-alike drugs

b. Dangerous abbreviations

c. Illegible handwriting

d. Leading and Trailing zeroes

a. Indomethacin

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• Indomethacin: A nonsteroidal anti-inflammatory drug (NSAID), not typically classified as a high-alert medication.

• Lidocaine: A local anesthetic and antiarrhythmic agent, is considered high-alert due to risks of toxicity.

• Colchicine: Used for gout, has a narrow therapeutic index and is considered high-alert.

• Heparin: An anticoagulant with a high risk of causing serious bleeding, definitely high-alert.

High-alert medication include all of the following EXCEPT;

a. Indomethacin

b. Lidocaine

c. Colchicine

d. Heparin

d. I, II and III

Drug interactions may be classed as;

I. pharmacokinetic interaction

II. Pharmacodynamic interaction

III. pharmaceutical interactions

a. I and III

b. I and II

c. II and III

d. I, II and III

b. I and II

Which of the following situations can lead to drug interactions?

I. Multiple drug therapy

II. Multiple prescribers

III. Patient compliance

a. I, II and III

b. I and II

c. I and III

d. II and III

c. pharmaceutical interaction

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• Pharmaceutical interactions occur before administration, when drugs are mixed improperly and cause physical or chemical incompatibilities (like precipitation, degradation).

• Pharmacokinetic and pharmacodynamic interactions happen after administration, affecting drug absorption, metabolism, or effects.

When drugs are mixed inappropriately in syringes or infusion prior to administration, it will give rise to a;

a. pharmacokinetic interaction

b. pharmacodynamic interaction

c. pharmaceutical interaction

d. beneficial interaction

c. IV piggyback

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• IV piggyback means giving a second solution (often antibiotics) intermittently through a Y-connector attached to the main IV line.

• IV push or bolus refers to a quick injection directly into the vein.

• IV infusion is a continuous drip of fluids or medications.

The intermittent administration of a second solution, like antibiotics, through a Y-tube in the existing IV line is referred to as;

a. IV push

b. IV bolus

c. IV piggyback

d. IV infusion

c. NSS

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• Amphotericin B should NOT be mixed with NSS because it can cause precipitation and reduce the drug’s effectiveness.

• It’s usually diluted in D5W (5% dextrose in water) to ensure stability.

• Lactated Ringer’s and Ringer’s Injection can also cause compatibility issues but NSS is specifically contraindicate

Amphotericin should not be admixed to;

a. D5W

b. Lactated Ringer's

c. NSS

d. Ringer's Injection

b. I and II

Admixture of any drug is NOT allowed in;

I. Blood derivatives

II. D5W

III. Amino acid

a. I only

b. I and II

c. I and III

d. I, II and

c. Controlled room temperature

Storage condition required for products that must be placed in an area with an air conditioning facility.

a. Cold temperature

b. Room temperature

c. Controlled room temperature

d. Cool temperature

c. Lactose

In compounding phenytoin capsule, the use of this capsule filler should be avoided since it can increase the toxicity of the drug.

a. Starch

b. Microcrystalline cellulose

c. Lactose

d. Bentonite

d. I, II and III

Which of the following can lead to overdosage?

I. Excessive amounts taken at one time

II. Doses repeated at too frequent intervals

III. Dose dumping from modified-release formulation

a. I and III

b. II and III

c. I and II

d. I, II and III

c. I and II

Antagonistic combinations are acceptable if;

I. it is used to modify the action of other ingredients

II. It is given as placebos

III. It will result to no therapeutic action or underdosage

a. I, II and III

b. II and III

c. I and II

d. I and III

c. asthmatics

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Asthmatics (c)

— due to risk of allergic reactions (penicillin) and asthma exacerbation (ASA).

—idiosyncratic and hypersensitivity

Penicillin and ASA are contraindicated to;

a. hypertensives

b. patients with ulcer

c. asthmatics

d. anemics

c. chloramphenicol

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Chloramphenicol can cause aplastic anemia, which means it stops the bone marrow from making enough blood cells.

Anemics should refrain from the use of;

a. nasal decongestants

b. NSAIDs

c. chloramphenicol

d. ASA

c. high blood pressure

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Decongestants can raise blood pressure by constricting blood vessels, so they are not recommended for patients with high blood pressure.

Cough and cold remedies with decongestants are NOT recommended to patients experiencing;

a. low RBC count

b. GI ulcer

c. high blood pressure

d. airway obstruction

d. Isordil

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• Viagra (sildenafil) + Isordil (isosorbide dinitrate, a nitrate) = severe hypotension

  • due to additive vasodilatory effects from increased nitric oxide–cGMP signaling.

• Centrum (multivitamins), Vitamin E, and Lipitor (atorvastatin) generally do not have significant interactions with Viagra.

So, Mr. Lu should avoid taking Viagra with Isordil.

Mr. Lu would like to take Viagra, but is also taking Centrum, Vit. E, Lipitor and Isordil. You would like to tell Mr. Lee that it can cause interaction with other agents he was taking. Which of the following agents can cause interaction with Viagra?

a. Centrum

b. Vitamin E

c. Lipitor

d. Isordil

b. Take the other drug at least one hour before or two hours after the intake of the first drug.

A patient with a prescription for Dulcolax EC came to a drugstore. The patient revealed that he is also on antacid therapy. Which of the following information should the pharmacist tell to the patient?

a. Take both drugs right after meal.

b. Take the other drug at least one hour before or two hours after the intake of the first drug.

c. Follow the intake of the laxative with milk for enhanced effect.

d. Crush the tablet and mixed it with antacid for better bioavailability.

c. diphenhydramine

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Here’s why, simply:

• Midazolam is a sedative (a benzodiazepine).

• Diphenhydramine is an antihistamine that can cause drowsiness.

• Taking them together can increase sedation too much, leading to excessive sleepiness or breathing problems.

The patient is taking Midazolam as a sleeping pill. Which of the following medications should not be taken concomitantly with midazolam?

a. allopurinol

b. amoxicillin

c. diphenhydramine

d. salbutamol

b. excessive drowsiness and sedation

What is the consequence of taking Diphenhydramine and midazolam?

a. excessive sweating

b. excessive drowsiness and sedation

c. chest pain

d. palpitation

b. Amoxicillin can decrease the effectiveness of the oral contraceptive

Ms. Cruz orders an Oral Contraceptive Pills (OCP) and Amoxicillin trihydrate 500 mg for two weeks. What is the potential problem recognized if the two drugs are taken concomitantly?

a. OCP can weaken the antibacterial property of amoxicillin

b. Amoxicillin can decrease the effectiveness of the oral contraceptive

c. Amoxicillin increases the risk of OCP's adverse drug reaction

d. There is no problem with the two drugs

c. take the two drugs as prescribed, but use mechanical method of contraception or practice abstinence

Refer to the previous number. What should be your recommendation if the two drugs are taken?

a. take the OCP qod

b. take amoxicillin 2 hours after taking OCP

c. take the two drugs as prescribed, but use mechanical method of contraception or practice abstinence

d. Stop Amoxicillin and continue the OCP

c. Do not refrigerate

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• Amoxicillin suspension usually needs to be refrigerated after reconstitution to maintain its stability.

• The other instructions—warning about penicillin allergy, shaking well, and completing the full course—are all correct and important.

So, “Do not refrigerate” does NOT apply.

If amoxicillin suspension was dispensed, which of the following information does NOT apply to the dispensed product?

a. Allergy to penicillin

b. Shake the bottle well

c. Do not refrigerate

d. Take for 7 days or complete the course

d. Ketoconazole - antacids

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• Tetracycline + milk, penicillamine + aluminum or iron, and fluoroquinolones + antacids all cause complexation — the drug sticks to metals and doesn’t get absorbed well.

• But ketoconazole + antacids doesn’t cause complexation. Instead, antacids change the stomach acid level, which stops ketoconazole from dissolving properly.

So, the answer is d. Ketoconazole - antacids because this interaction is NOT complexation.

The mechanism of interaction of the following is complexation EXCEPT;

a. Tetracycline-milk

b. Penicillamine-Aluminum or Iron salts

c. Flouroquinolones - Al and Mg containing antacids

d. Ketoconazole - antacids

b. rifampicin

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• Rifampicin = red-orange discoloration of urine, sweat, and tears.

• Vitamin B2 (Riboflavin) = bright yellow urine

• chloroquine =bluish or greenish urine discoloration (rare)

• vitamin C =clear or slightly yellow urine

A red orange urine is to be expected while taking this drug

a. vitamin B2

b. rifampicin

c. chloroquine

d. vitamin C

d. antacids

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• Anticholinergics, metoclopramide, and cathartics affect GI motility and gastric emptying, which can change how drugs are absorbed.

• Antacids mainly alter the gastric pH but do not significantly affect GI motility or gastric emptying.

The following agents alter GI absorption of drugs taken concomitantly by altering GI motility and gastric emptying EXCEPT;

a. anticholinergics

b. metoclopramide

c. cathartics

d. antacids

a. I, II and III

The bioavailability of bisphosphonates may be markedly reduced if taken with;

I. Coffee

II. Orange juice

III. Mineral water

a. I, II and III

b. II and III

c. I and II

d. I and III

d. Miglitol

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• Captopril,Alendronate, and Theophylline (controlled-release) = taken with empty stomach

• Miglitol = is an alpha-glucosidase inhibitor used in diabetes and should be taken with food to slow carbohydrate absorption and control blood sugar spikes.

In some situation, medication should be administered with food to obtain optimum benefit. This is TRUE with;

a. Captopril

b. Alendronate

c. theophylline in controlled release form

d. Miglitol

a. at the start (at first bite) of each meal

For optimum benefit associated with alpha-glucosidase inhibitors used in diabetes, these should be taken;

a. at the start (at first bite) of each meal

b. at least ½ hour before the first food

c. with plain water only

d. after each meal

c. interruption of the enterohepatic circulation

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Antibiotics reduce gut bacteria that normally help recycle estrogen through enterohepatic circulation.

By reducing microbial flora, antibiotics decrease the effectiveness of oral contraceptives. This is due to:

a. increased extent of GI metabolism

b. alteration of Vitamin K production by microorganism

c. interruption of the enterohepatic circulation

d. reduced absorption of oral contraceptives

b. an immediate-release formulation

Food does NOT alter the activity of theophylline significantly when the drug is administered in;

a. a controlled-release form

b. an immediate-release formulation

c. a transdermal patch

d. injection form

c. Planogram

A diagram that shows how and where specific retail merchandise should be placed on shelves or display cabinets.

a. Pharmacy Lay-out

b. Pharmagram

c. Planogram

d. Pharmacy design

a. Warfarin + Phenylbutazone

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• Warfarin + Phenylbutazone interaction is mainly due to displacement from protein-binding sites, not pH changes.

• The others involve antacids, which alter gastric pH and affect drug solubility or absorption.

The following drug interaction may manifest alteration of pH, EXCEPT:

a. Warfarin + Phenylbutazone

b. Antacid + Salicylates

c. Antacid + Bisacodyl

d. Antacid + Ketoconazole

c. hypertensive crisis

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• Isocarboxazid is an MAOI (monoamine oxidase inhibitor).

• tyramine-rich foods (cheese or Chianti wine) + MAOIs (Isocarboxazid) = hypertensive crisis due to excessive norepinephrine release.

Consumption of cheese or Chianti wine with Isocarboxazid can lead to;

a. increased bleeding

b. diminished antihypertensive activity

c. hypertensive crisis

d. decreased antidepressant property

a. displacement of warfarin from protein-binding sites

Warfarin and sulfonamide given concurrently leads to increased anticoagulant effect. This may be due to;

a. displacement of warfarin from protein-binding sites

b. stimulation of warfarin's metabolism

c. increased absorption of warfarin

d. decrease vit. K synthesis

a. decreased effectiveness of the antifungal agent

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• Ketoconazole requires an acidic stomach environment for proper absorption.

• Omeprazole (a proton pump inhibitor) reduces stomach acid, raising gastric pH.

• This reduces ketoconazole absorption, lowering its effectiveness.

Administration of Ketoconazole to a patient who is currently taking Omeprazole would likely result to:

a. decreased effectiveness of the antifungal agent

b. decreased activity of the PPI

c. enhanced activity of antifungal agent

d. increased activity of the antiulcer drug

b. adsorbption

Antidiarrheal agents decreases absorption of other agents concurrently by

a. increasing Gi motility

b. adsorbption

c. absorption

d. decreasing GI motility

c. bile acid sequestrants

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• Bile acid sequestrants bind bile acids in the intestine, reducing fat absorption.

• This can lead to malabsorption of fat-soluble vitamins (A, D, E, K) and some drugs.

Use of hypolipidemic drugs result to malabsorption of fat-soluble vitamins and certain drugs

a. statins

b. fibrates

c. bile acid sequestrants

d. niacin

a. Resin - Digitalis glycosides

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• Cholestyramine and colestipol are bile acid sequestrants (resins) that bind lipophilic substances in the gut.

  • Digitalis glycosides → Useful in digitalis toxicity (reduces absorption).

  • Fat-soluble vitamins (A, D, E, K) → Undesirable, can cause deficiencies.

  • Warfarin → Undesirable, reduces anticoagulant effect.

  • Aspirin (ASA) → Undesirable, reduces absorption and effect.

Cholestyramine and colestipol binds with a variety of lipophilic materials taken concomitantly with it. Which of these interactions with resin could be of clinical value?

a. Resin - Digitalis glycosides

b. Resin - fat soluble vitamins

c. Resin - Warfarin

d. Resin - ASA

d. pravastatin

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Pravastatin absorption is not significantly affected by food, so food does not enhance its absorption.

Absorption of HMG-CoA reductase inhibitors can be enhanced with food with the exception of:

a. rosuvastatin

b. atorvastatin

c. simvastatin

d. pravastatin

d. lovastatin

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Statins like lovastatin are best taken at night because cholesterol synthesis in the liver is highest during nighttime. Taking lovastatin in the evening or at bedtime maximizes its effectiveness in lowering LDL cholesterol.

Which of the following anti -cholesterol drugs are best taken at night?

a. niacin

b. gemfibrozil

c. colestipol

d. lovastatin

a. alteration of pH

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Bisacodyl is a stimulant laxative that requires an acidic environment to be activated (hydrolyzed to its active form). Milk, being alkaline, can raise the pH in the stomach, which may delay or reduce bisacodyl’s activation and absorption. So the interaction mainly occurs due to alteration of pH by milk.

Bisacodyl interacts with milk through what mechanism?

a. alteration of pH

b. complexation

c. adsorption

d. alteration of motility rate

a. I, II, and III

Moxifloxacin product labeling recommends that this antibacterial agent should be taken at least 4 hours before or 8 hours after taking;

I. Antacid preparations

II. Multivitamins with Zinc

III. Yogurt

a. I, II, and III

b. I and II

c. I and III

d. II and III

b. I and II

Which of the following statements is TRUE regarding the interactions of Penicillamine?

I. Absorption of penicillamine is reduced by aluminum and iron salts through chelation mechanism

II. Antacid and penicillamine should be administered at least 2 hours apart

III. Penicillamine should be administered with metals preparation

a. I, II and III

b. I and II

c. I and III

d. II and III

d. I, II, and III

The consumption of grapefruit juice has been reported to increase the serum concentration of some drugs. Which of the following drugs can be affected by grapefruit juice?

I. Amlodipine

II. Lovastatin

III. Cyclosporine

a. I and II

b. I and III

c. II and III

d. I, II, and III

b. 2 hrs

If an antacid is to be taken with ketoconazole, the two drugs be administered at least _____ apart to avoid interaction.

a. 1 hr

b. 2 hrs

c. 3 hrs

d. 4 hrs

d. I and III

Antibiotics enhance the pharmacologic action and increase the toxicity of the following drugs due to alteration of GI flora.

I. anticoagulant

II. oral contraceptives

III. digoxin

a. I, II and III

b. II and III

c. I and II

d. I and III

c. displacement from plasma protein binding site

What is the mechanism of interaction between methotrexate and salicylates?

a. induction of metabolism

b. inhibition of metabolism

c. displacement from plasma protein binding site

d. additive effect

a. CLINISTIX ®

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• Ampicillin can cause false-positive urine glucose tests with copper reduction methods (e.g., CLINITEST®, Benedict’s, Fehling’s), because it’s a reducing agent.

• CLINISTIX® uses a glucose oxidase method, which is specific for glucose and not affected by ampicillin.

Ampicillin will produce a false-positive reactions when testing for the presence of glucose in urine using the following, EXCEPT:

a. CLINISTIX ®

b. CLINITEST ®

c. Benedict's Solution

d. Fehling's Solution

d. III only

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• Concurrent use of alcohol and benzodiazepines primarily results in enhanced central nervous system (CNS) depression, which can lead to coma and respiratory depression

• Alcohol (CNS depressant) + Benzodiazipine (CNS depressant) = Coma

Concurrent use of alcohol with benzodiazepines result to;

I. Hyperexcitability

II. Hallucinations

III. Coma

a. I, II and III

b. I and II

c. II and III

d. III only

b. I and III

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Explanation:

• Phenobarbital is a well-known enzyme inducer, increasing the activity of drug-metabolizing enzymes (especially CYP450 enzymes).

• Smoking also induces certain CYP enzymes, like CYP1A2, increasing metabolism of some drugs.

• Grapefruit juice, on the other hand, inhibits CYP3A4 enzymes, decreasing metabolism of drugs.

So only phenobarbital and smoking increase enzyme activity.

The activity of drug metabolizing enzymes can be increased by;

I. Phenobarbital

II. Grapefruit juice

III. Smoking

a. I and II

b. I and III

c. III only

d. I, II and III

d. Omeprazole beads in apple sauce

Which of the following interactions is not a harmful food-drug interaction?

a. Raw green salads with warfarin on DVT prophylaxis

b. Milk with doxycycline

c. Grapefruit juice and cyclosporine

d. Omeprazole beads in apple sauce

d. Penicillin with probenecid to prolong the antibacterial effect to treat STD

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Probenecid slows down how fast penicillin leaves the body, so the antibiotic works longer and better to treat infections.

• Citalopram and MAOI together can cause serotonin syndrome and is contraindicated.

• ASA and warfarin together increase bleeding risk, which is generally harmful, not therapeutic.

• Levofloxacin with antacid reduces absorption and efficacy, which is harmful, not beneficial.

Which of the following is a valid therapeutic use of a drug interaction?

a. Citalopram and MAOI to treat depression

b. ASA and warfarin to enhance anticoagulation

c. Levofloxacin taken with antacid to decrease GI intolerance

d. Penicillin with probenecid to prolong the antibacterial effect to treat STD

d. competition for tubular secretion

The mechanism behind Probenecid and Penicillin interaction is;

a. enzyme induction

b. enzyme inhibition

c. alteration in gastric emptying

d. competition for tubular secretion

c. Enzyme induction

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• St. John’s Wort induces CYP3A4 enzymes, which increases the metabolism of indinavir, reducing its blood levels and effectiveness in antiretroviral therapy.

• St. John’s Wort makes the body break down indinavir faster, so the medicine doesn’t work as well.

Indinavir Antiretroviral Therapy (ART) taken concomitantly with St. John's Wort for depression leads to decrease ART efficacy. This is most likely due to;

a. Additive toxicity

b. Antagonistic effect

c. Enzyme induction

d. Enzyme Inhibition

c. I and II

Drugs having similar pharmacological effects include;

I. antipsychotics - antihistamines - alcohol

II. antipsychotic - TCA's - trihexyphenidyl

III. thiazide diuretics - oral hypoglycemics

a. I, II and III

b. II and III

c. I and II

d. III only

d. blocking the transport of drug

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Fexofenadine is a second-generation antihistamine used to treat allergies like hay fever and urticaria (hives).

Key points about fexofenadine:

• It blocks H1 histamine receptors, reducing allergy symptoms like sneezing, itching, and runny nose.

• It does not cause drowsiness much because it doesn’t cross the blood-brain barrier easily (unlike first-generation antihistamines).

• It’s non-sedating and generally well tolerated.

Grapefruit juice decreases the efficacy of Allegra (fexofenadine) by;

a. increasing the activity of drug metabolizing enzymes

b. inhibiting the cytochrome P450 enzymes

c. increasing the absorption of drugs

d. blocking the transport of drug

Enzyme inhibitor

Grapefruit juice is an ____ [enzyme inducer/ enzyme inhibitor]

a. increases the enzyme activity

Chronic use of alcohol may;

a. increases the enzyme activity

b. inhibits hepatic enzymes

c. decrease gastric emptying

d. enhance elimination of other agents taken concurrently

Enzyme inducer

Chronic Alcoholism is an ____ [enzyme inducer/ enzyme inhibitor]

Enzyme inhibitor

Acute Alcoholism is an ____ [enzyme inducer/ enzyme inhibitor]

b. Cimetidine

Inducers of CYP3A4 include all of the following EXCEPT;

a. Phenobarbital

b. Cimetidine

c. St. John's wort

d. Carbamazepine

b. Intake of Rifampin

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• Macrolide antibiotics, acute alcohol use (in non-alcoholics), and grapefruit juice inhibit certain drug-metabolizing enzymes.

• Rifampin is a strong enzyme inducer, meaning it increases enzyme activity, not inhibits it.

Enzyme inhibition may be precipitated by all of the following EXCEPT;

a. Use of macrolide antibiotics

b. Intake of Rifampin

c. Acute use of alcohol by non alcoholic individuals

d. Consumption of grapefruit juice

Enzyme inducer

Rifampin is an____ [enzyme inducer/ enzyme inhibitor]

c. I and III

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NOTE:

Explanation:

• I. True: HIV protease inhibitors are mostly broken down by the CYP3A4 enzyme.

• II. False: Rifampin is a strong enzyme inducer, not an inhibitor. It speeds up enzyme activity, which lowers HIV protease inhibitors’ levels, so they don’t work well together.

• III. True: Using enzyme inducers with HIV protease inhibitors can reduce their effectiveness by increasing their breakdown.

So, statements I and III are true, but II is false.

TRUE statements include;

I. HIV protease inhibitors are extensively metabolized via CYP3A4 pathways

II. Rifampin is a strong enzyme inhibitor that is contraindicated with HIV protease inhibitors

III. Concurrent use of HIV protease inhibitor and enzyme inducers could compromise the effectiveness of the antiretroviral regimen for HIV infection

a. I, II and III

b. II and III

c. I and III

d. I and II

b. Insomnia

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Explanation:

• Smoking is a stimulant and can cause insomnia or reduce the sedative effects of lorazepam. So, even though lorazepam is meant to help with anxiety or sleep, smoking can interfere and make it harder to sleep.

A smoker was prescribed with lorazepam. What would likely happen if he continuously smokes while on the drug therapy?

a. Prolonged sleep

b. Insomnia

c. no effect

d. coma and death

c. increased risk of thrombus formation

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Explanation:
Phenobarbital induces liver enzymes that increase the metabolism of warfarin, lowering warfarin’s blood levels. This reduces warfarin’s anticoagulant effect, increasing the risk of blood clots (thrombus formation).

Phenobarbital can increase the rate of metabolism of warfarin. The result of this interaction is;

a. increased anticonvulsant property of Phenobarbital

b. decreased anticonvulsant property of Phenobarbital

c. increased risk of thrombus formation

d. decreased risk of thrombus formation

b. I and III

The efficacy of estrogens and progestins as an oral contraceptive may be reduced by drugs that can increase their metabolism. Which of the following agents can cause that interaction?

I. Phenobarbital

II. Ampicillin

III. Rifampin

a. I, II and III

b. I and III

c. I and II

d. II and III

Enzyme inducer

Phenobarbital is an ____ [enzyme inducer/ enzyme inhibitor]

b. pyridoxine

This agent reduces the action of levodopa by accelerating its decarboxylation to dopamine in the peripheral tissues.

a. carbidopa

b. pyridoxine

c. entacapone

d. dopamine