Pharmacology Exam 2 Prototype Drugs

Alpha adrenergic blocker

prazosin (Minipress)

Alpha adrenergic blocker

MOA: competes with NE to selectively binds to alpha1-adrenergic receptors on vascular smooth muscles in the arterioles and veins

Primary uses:

- lower BP by causing vasodilation

- relaxes smooth muscle in the bladder neck and prostate

Alpha adrenergic blocker

Adverse effects:

- orthostatic hypotension

- reflex tachycardia

- nasal congestion

- impotence

- unconsciousness

- dizziness

- drowsiness

- light-headedness

Contraindications:

- pregnancy and lactation

Parasympathomimetic (cholinergic agonist)

bethanechol

Parasympathomimetic (cholinergic agonist)

MOA: binds to muscarinic receptors to stimulate a parasympathetic-like response and stimulates smooth muscle contraction

Primary uses:

- reduces intraocular pressure (used for glaucoma)

- increases gastric secretions and motility (used post-surgery)

- stimulates skeletal muscle contraction (treatment of myasthenia gravis)

Parasympathomimetic (cholinergic agonist)

Adverse effects:

- bradycardia

- hypotension

- syncope

- salivation

- abdominal cramping

- sweating

- cardiac conduction abnormalities (AV block)

- circulatory collapse

- cardiac arrest

- headache

- dizziness

- convulsions

- ataxia

- increased secretions

- N&V

- increased bronchial secretions

- bronchospasms

- lacrimation

- miosis

(parasympathetic effects)

Contraindications:

- asthma

- epilepsy

- Parkinson's

- hyperthyroidism

- PUD

- bradycardia

- pregnancy/lactation

- children younger than 8

- use with caution for pts with suspected obstruction, active ulcers, inflammatory diseases, urinary obstruction, COPD

Cholinergic blocker

dicyclomine (Bentyl)

Cholinergic blocker

MOA: has an anticholinergic effect on ACh receptor sites and acts directly on smooth muscle

Primary uses: calms functional disturbances of the GI tract to reduce IBS, etc.

Cholinergic blocker

Adverse effects:

- dry mouth

- upset stomach

- vomiting

- constipation

- stomach pain

- gas or bloating

- loss of appetite

- dizziness

- tingling

- headache

- drowsiness

- weakness

- blurred vision

- double vision

- difficulty urinating

Contraindications:

- hypersensitivity

- angle-closure glaucoma

- GI tract obstruction

Cholinergic receptor blocker

atropine (Atro-Pen)

Cholinergic receptor blocker

MOA: blocks muscarinic receptors, and thus, the action of ACh and the P-ANS response

Primary uses:

- calm hypermotility of the GI tract (e.g. IBS)

- suppress secretions during surgery

- increase HR

- dilate pupils during eye exam

- cause bronchodilation in pts with asthma

- treat reflexive bradycardia and hypertrophic pyloric stenosis in infants

Cholinergic receptor blocker

Adverse effects:

- dry mouth

- constipation

- urinary retention

- increased HR

- delirium

- coma

Contraindications:

- glaucoma

- obstructive GI disorders

- paralytic ileus

- bladder neck obstruction

- benign prostatic hyperplasia

- myasthenia gravis

- cardiac insufficiency

- acute hemorrhage

Calcium channel blocker

nifedipine (Adalat CC, Procardia XL)

Calcium channel blocker

MOA: causes smooth muscle relaxation by blocking the binding of Ca2+ to receptors to prevent muscle contraction

Primary uses:

- treatment of HTN, angina, and dysrhythmias

- decreases peripheral smooth muscle tone, SVR, and BP

Calcium channel blocker

Adverse effects:

- reflex tachycardia

- headache

- dizziness

- peripheral edema

- constipations

- flushing

- paradoxical anginal pain

Contraindications:

- hypersensitivity

- abruptly discontinuing the medication

- grapefruits

ACE inhibitor

lisinopril (Prinivil, Zestril)

ACE inhibitor

MOA: reduce angiotensin II and aldosterone levels

Primary uses:

- decrease BP, SVR, and preload

- prevent complications after an MI

- help with ventricular remodeling

- pts with HTN and HF

- reduce glomerular filtration pressure and proteinuria

ACE inhibitor

Adverse effects:

- orthostatic hypotension

- fatigue

- dizziness

- headache

- mood changes

- impaired taste

- GI distress

- angina

- hyperkalemia

- possible hyperkalemia

- dry, non-productive cough

- angioedema

- fatal injury or death

- first-dose hypotension

Contraindications:

- hyperkalemia

- angioedema caused by ACE inhibitor therapy

- pregnancy and lactation

ARB (angiotensin II receptor blocker)

losartan

ARB (angiotensin II receptor blocker)

MOA: selectively block the binding of angiotensin II to the angiotensin II receptors in vascular smooth muscle and the adrenal gland and block vasoconstriction and the secretion of aldosterone

Primary uses:

- treatment of HTN and HR

ARB (angiotensin II receptor blocker)

Adverse effects:

*do not cause a dry cough or risk of hyperkalemia

- chest pain

- fatigue

- hypoglycemia

- diarrhea

- anemia

- weakness

Contraindications:

- ACE inhibitors

- pregnancy or lactation

Alpha1-adrenergic blocker

doxazosin (Cardura)

Alpha1-adrenergic blocker

MOA: selectively blocks alpha1-adrenergic receptors which are located on smooth muscle

Primary uses:

- decrease BP and peripheral vascular resistance

- decrease urinary obstruction due to BPH

Alpha1-adrenergic blocker

Adverse effects:

- orthostatic hypotension

- bradycardia with reflex tachycardia

- dry mouth

- drowsiness/sedation

- constipation

- depression

- edema

- sexual dysfunction

- headache

- sleep distrubrances

- nausea

- rash

- rebound HTN with abrupt discontinuation

Contraindications:

Beta blocker

metoprolol (Lopressor, Toprol XL)

Beta blocker

MOA: selectively blockers beta1-adrenergic receptors

Primary uses:

- decrease cardiac workload by reducing sympathetic stimulation

- treatment of HF, angina, HTN, and MI complications

Beta blocker

Adverse effects:

- sexual dysfunction

- drowsiness

- fatigue

- insomnia

Contraindications:

- abruptly stopping the medication

- cardiogenic shock

- sinus bradycardia

- heart block

- hypotension

- overt cardiac failure

- use cautiously in pts with bronchospasm and asthma

Direct vasodilator

hydralazine (Apresoline)

Direct vasodilator

MOA: acts directly on the arteriolar or venous smooth muscle to cause vasodilation

Primary uses:

- treatment of acute HTN crisis

Direct vasodilator

Adverse effects:

- headache

- reflex tachycardia

- palpitations

- flushing

- nausea

- diarrhea

- lupus-like syndrome

- Na+ and H2O retention

Contraindications:

- angina

- rheumatic heart disease

- MI

- tachycardia

- lupus

Cardiac glycoside

digoxin (Lanoxin, Lanoxicaps)

Cardiac glycoside

MOA: inhibits Na+-K+ ATPase which causes Na+ to accumulate, creating a more forceful cardiac contraction

Primary uses:

- increases CO

- treatment of HF and exercise intolerance

Cardiac glycoside

Adverse effects:

- very narrow therapeutic window

- dysrhythmias (hypokalemia or impaired renal function)

- N&V

- fatigue

- anorexia

- visual disturbances (halos, yellow/green tinge, blurring)

Contraindications:

- AV block or ventricular dysrhythmias unrelated to HF

- use with caution for pts with renal impairment, MI, cor pulmonale, hypothyroidism, or elderly

Statin (HMG-CoA Reductase Inhibitor)

Atorvastatin (Lipitor)

Statin (HMG-CoA Reductase Inhibitor)

MOA: inhibits HMG-CoA reductase which is a critical enzyme in the biosynthesis of cholesterol

Primary uses: reduces serum-lipid levels

Statin (HMG-CoA Reductase Inhibitor)

Adverse effects:

- muscle or joint pain

- rhabdomyolysis

- pregnancy category X

- headache

- fatigue

- intestinal cramping

- diarrhea

- constipation

- liver damage

Contraindications:

- grapefruit juice

- liver disease

- unexplained, persistent elevation of serum transaminases

Bile acid sequestrant

cholestyramine (Questran)

Bile acid sequestrant

MOA: binds with bile acids to increase the excretion of cholesterol in the stool

Primary uses: decrease cholesterol levels

Bile acid sequestrant

Adverse effects:

- bloating

- diarrhea

- gas

- nausea

- binding to other medications, fat soluble vitamins, and folic acid

Contraindications:

- total biliary obstruction

Antilipemic

niacin (Niaspan)

Antilipemic

MOA: N/A

Primary uses: decrease VLDL, LDL, and triglyceride levels and increase HDL levels

Antilipemic

Adverse effects:

- flushing

- hot flashes

- nausea

- excess gas

- diarrhea

- increases blood glucose

- hepatotoxicity

- gout

Contraindications:

- diabetes mellitus

Nitrate

nitroglycerin (Nitrostat, Nitro-Bid, Nitro-Dur)

Nitrate

MOA: dilate the arterial and venous smooth muscle and coronary arteries

Primary uses:

- relax arterial and venous smooth muscle

- dilate coronary arteries

- reduce cardiac workload

- lower myocardial O2 demand

- short-acting: terminate acute angina episodes

- long-acting: decrease severity and frequency of angina episodes

Nitrate

Adverse effects:

- headache

- hypotension

- dizziness

- reflex tachycardia

Contraindications:

- preexisting hypotension

- high intracranial pressure

- head trauma

- pericardial tamponade

- constrictive pericarditis

- glaucoma

- dehydration or hypovolemia

- concurrent use of phosphodiesteraes-5 inhibitors (e.g. Viagra) due to risk of life-threatening hypotension or cardiovascular collapse

- BP <90/60 or pulse of >100 BPM

Beta blocker

atenolol (Tenormin)

Beta blocker

MOA: selectively blocks beta1-adrenergic receptors in the heart

Primary uses:

- treatment of angina pain

- reduce cardiac workload, slow HR, and reduce contractility

Beta blocker

Adverse effects:

- fatigue

- insomnia

- drowsiness

- impotence

- bradycardia

- confusion

Contraindications:

- pulse <60 or pt is hypotensive

- severe bradycardia

- AV heart block

- cardiogenic shock

- decompensated HF

- severe hypotension

- abrupt discontinuation

Calcium channel blocker

diltiazem (Cardizem, Cartia XT, Dilacor XR)

Calcium channel blocker

MOA: inhibits the transport of Ca2+ into the myocardial cells

Primary uses:

- relax arteriolar smooth muscle and cardiac workload

- increase O2 in the myocardium

- treatment of atrial dysrhythmias, HTN, and stable/vasospastic angina

Calcium channel blocker

Adverse effects:

- dizziness/lightheadedness

- flushing

- headache

- weakness

- slow HR

- vomiting

- diarrhea

- constipation

- nasal congestion

- cough

- swelling of the face, eyes, lips, tongue, hands, arms, feet, ankles, or lower legs

- difficulty breathing/swallowing

- fainting, rash, yellowing skin or eyes

- extreme tiredness/lack of energy

- unusual bleeding/bruising

- loss of appetite

- flu-like symptoms

- pain in URQ

- increased frequency/severity of angina

Contraindications:

- AV heart block

- sick sinus syndrome

- severe hypotension

- bleeding aneurysm

- intracranial surgery

- use cautiously in patients with renal or hepatic impairment

Thrombolytic

reteplase (Retavase)

Thrombolytic

MOA: cleaving plasminogen to form plasmin which then degrades the fibrin matrix of thrombi

Primary uses: dissolve clots obstructing coronary arteries

Thrombolytic

Adverse effects:

- abnormal bleeding

- dysrhythmias

- narrow margin of safety

Contraindications:

- active bleeding

- history of stroke

- recent surgical procedures