Cold-cough-flu-COVID matrix

What drug class are pseudoephedrine and phenylephrine (Sudafed, Sudafed PE)?

Systemic (oral) decongestants / sympathomimetics

What is the MOA of oral decongestants like pseudoephedrine/phenylephrine?

They stimulate alpha-adrenergic receptors (and have some beta-agonist effects) in the nose/sinuses, constricting blood vessels and decreasing sinusoidal vessel engorgement and mucosal edema

What symptom(s) are pseudoephedrine/phenylephrine used to treat?

Nasal/sinus congestion; also can help cough related to post-nasal drip and may help eustachian tube congestion

Why do pseudoephedrine and phenylephrine cause raised BP, tachycardia, and arrhythmias?

Because of systemic alpha and beta agonist stimulation (norepinephrine-like effects) - this causes essentially all of the side effects

Name the CNS-related side effects of oral decongestants.

Insomnia, anxiety, nervousness, restlessness, tremor, anorexia (from stimulation of CNS by crossing the blood-brain barrier)

Name the urinary/GU side effects of oral decongestants and why they occur.

Urinary retention and stimulation of urethra/prostate smooth muscle, due to alpha agonism

What is the onset of action for oral decongestants?

Within 30 minutes to 2 hours; available as short-acting and long-acting (12 hr, 24 hr) tablets

Why is pseudoephedrine kept behind the pharmacy counter?

Because it can be used to manufacture methamphetamine (abuse concern)

Is phenylephrine or pseudoephedrine more effective as an oral decongestant?

Pseudoephedrine is typically more effective than phenylephrine

What age is pseudoephedrine/phenylephrine approved for per the FDA, and what age do manufacturers voluntarily recommend?

FDA: 2 years and older; manufacturers voluntarily increased the age to 4+ due to risk of overdose and lack of efficacy data in younger children

Why should patients with hyperthyroidism use oral decongestants with caution?

Because the drugs are stimulating to the cardiovascular and central nervous systems

Why should patients with cardiac problems or uncontrolled hypertension avoid oral decongestants?

Due to cardiovascular stimulation (increased BP, HR, palpitations, arrhythmia risk) from the drug's CV stimulating effects

Why should patients with BPH/prostate enlargement avoid oral decongestants?

The drugs contract smooth muscle around the urethra (alpha agonism) and can further inhibit urination

Why should diabetic patients use oral decongestants with caution?

Potential for peripheral vasoconstriction

Why are older adults generally cautioned against oral decongestants?

They often have many of the disease states (cardiac, BPH, hyperthyroid, etc.) that make these drugs risky

What rare but serious eye emergency can oral decongestants cause?

Acute angle-closure crisis / closed-angle glaucoma (emergency vision loss) - very rare

Are oral decongestants (pseudoephedrine/phenylephrine) safe in pregnancy and lactation?

AVOID - potential for birth defects and decreased milk production

What drug class is pseudoephedrine/phenylephrine contraindicated with, and why is this notable?

Contraindicated with MAOIs (rarely used antidepressants)

What drug class are oxymetazoline, topical phenylephrine, and naphazoline (Afrin, Neo-Synephrine)?

Topical nasal decongestants

What is the MOA of topical nasal decongestants?

Stimulate alpha-adrenergic receptors in the nose/sinuses, constricting blood vessels and decreasing sinusoidal vessel engorgement and mucosal edema (same MOA as oral, but applied topically)

What symptom do topical nasal decongestants treat?

Nasal/sinus congestion

What is the onset of action for topical nasal decongestants?

Rapid - within minutes

Why are topical nasal decongestants preferred over oral decongestants in pregnancy, breastfeeding, heart disease, and BPH?

They lack significant systemic absorption/side effects, so they are safer for these conditions than oral decongestants

Which topical decongestant is the least systemically absorbed and is preferred, and how often is it dosed?

Oxymetazoline - preferred agent, long acting, dosed twice a day (other topical decongestants are dosed every 4-6 hours)

What condition can occur with topical nasal decongestant overuse beyond 3-7 days?

Rhinitis medicamentosa (rebound congestion from overuse/too-long duration)

What local side effects can topical nasal decongestants cause?

Dry nose, bleeding due to dryness, local irritation (sneezing/burning/stinging), and trauma from improper use

What patient counseling point is important for topical nasal decongestant sprays/bottles?

Viral contamination can occur if the product is shared - keep the bottle clean and use separate bottles for separate people

Are topical nasal decongestants safe in pregnancy and lactation?

Yes - safe

What drug class is nasal saline (Neilmed, Ayr, Ocean sprays)?

Moisturizer

What is the MOA of nasal saline?

Relieves nasal irritation and dryness; aids in removal of thick/dried mucus from the nose

What symptoms does nasal saline treat?

Nasal congestion and dryness; withdrawal from nasal decongestants

What side effects can nasal saline cause?

Runny nose, mild stinging/burning (more comfortable if warmed ~30 seconds)

What ages can nasal saline be used in, and is it safe in pregnancy/lactation?

OK to use in any age; safe in pregnancy and lactation

What is the maximum recommended frequency for nasal irrigation?

BID (twice daily)

Is nasal irrigation or nasal saline spray more effective, and who should avoid irrigation?

Nasal rinse/irrigation is more effective than saline spray or drops, but is not recommended in infants and children who cannot administer it themselves

What are the cons of nasal saline irrigation?

Can be uncomfortable, and requires boiled/distilled water

What drug class are menthol and camphor (Vicks, Mentholatum)?

Local anesthetic / topical antitussive

What is the general MOA of menthol?

Stimulates TRPM8 receptors, producing an anesthetic (cooling) sensation

What is the MOA of menthol lozenges for cough?

Lozenges decrease throat irritation and increase saliva, causing a reduction in cough reflex sensitivity

What is the MOA of menthol/camphor chest rub for nasal/chest congestion?

Vapors stimulate sensory nerve endings within the nose/chest mucosa, creating a local anesthetic sensation and a sense of improved airflow

What symptoms do menthol lozenges treat?

Cold sensation/numbness in mouth, sore throat (localized), and can help dry cough

What symptoms does menthol/camphor chest rub treat?

Nasal or chest congestion (rub), and dry cough (rub)

What side effects can menthol lozenges cause?

Bad taste from menthol, numb taste buds which can reduce taste of foods

What side effects can menthol/camphor chest rub cause?

Ointments are greasy; localized skin irritation may occur with topical products; can cause burns if heated/vaporized and gets on skin

Are menthol lozenges safe in pregnancy and breastfeeding?

Yes - menthol lozenges are considered safe

Is menthol/camphor chest rub recommended in pregnancy and breastfeeding, even though the reference book says camphor is compatible?

Not recommended - if absorbed systemically it crosses the placenta and the fetus cannot metabolize it; compatible with breastfeeding but not recommended due to close proximity to the breasts

Why is camphor especially dangerous if a child eats the chest rub ointment?

As little as 4 teaspoons of camphor-containing ointment can be deadly - it can cause overdose in children

What precaution should be taken when applying menthol/camphor rub to young children's feet?

Cover with socks so they don't accidentally eat it

What is a choking risk associated with menthol/camphor lozenges?

Choking risk in children under 4-6 years and sometimes older adults

What ages are menthol/camphor lozenges and ointment approved for?

Ointment: adults and children 2+; lozenges: adults and children 6+

What drug class is dextromethorphan (Robitussin, Delsym)?

Antitussive (cough suppressant) - nonopioid

What is the MOA of dextromethorphan?

A nonopioid that acts centrally in the medulla to increase the cough threshold

What is the MOA of codeine as an antitussive?

An opioid that acts centrally on the cough control center (medulla) to increase the cough threshold

What symptom does dextromethorphan/codeine treat?

Dry cough

What side effects are associated with dextromethorphan?

Stomach discomfort (from sugar content), drowsiness/CNS depression, and abuse potential ('robotripping' - euphoria, hallucinations)

What side effects are associated with codeine?

Euphoria/risk of addiction, nausea/vomiting, sedation, dizziness, constipation, and respiratory depression (in overdose)

Is dextromethorphan safe in kids, older adults, pregnancy, and lactation?

Yes - safe in kids and older adults, and safe in pregnancy and lactation

When should dextromethorphan NOT be used for cough?

Not for productive coughs, unless the patient cannot sleep or the cough is interfering with ADLs

What caution applies to dextromethorphan and alcohol/CNS depressants?

Can be abused and should not be used with alcohol or CNS depressants

What drug interaction is dextromethorphan contraindicated with?

Contraindicated with MAOIs (rarely used antidepressants) - a DDI risk

Is codeine safe in children, pregnancy, or breastfeeding?

AVOID - not to be used in kids, pregnancy, or breastfeeding mothers

What is the scheduling status of codeine, and is it available OTC?

Codeine is a CS-V (Controlled Substance V) and is OTC in certain states

What age is dextromethorphan approved for per FDA vs. manufacturer recommendation?

FDA: 2+ years; manufacturer: 4+ years

What is the max dextromethorphan dose for a child aged 4-6 years?

30 mg/day maximum

What is the max dextromethorphan dose for a child aged 6-12 years?

60 mg/day maximum

What is the max dextromethorphan dose for a patient over 12 years?

120 mg/day maximum

What is the minimum age for OTC codeine use?

Over 18 years of age

What drug class is diphenhydramine (Benadryl), chlorpheniramine, brompheniramine, and doxylamine?

Sedating / first-generation antihistamines

What is the general MOA of first-generation antihistamines?

Block histamine at central and peripheral histamine-1 (H1) receptor sites

What is the nasal-symptom MOA of first-generation antihistamines?

Act peripherally in the nose to dry up nasal secretions (anticholinergic effect)

What is the cough MOA of first-generation antihistamines?

Act centrally in the medulla to increase the cough threshold, AND decrease/dry up post-nasal drip peripherally to reduce cough

What is the insomnia/sedation MOA of first-generation antihistamines?

Cross the blood-brain barrier (BBB) to cause sedation

Why are second-generation antihistamines (Claritin, Zyrtec, Allegra) not effective for cough/cold?

They do not have the central/anticholinergic peripheral effects that first-generation antihistamines have

What symptoms do first-generation antihistamines treat in cough/cold?

Dry cough, rhinorrhea, and can help with sleep

List the anticholinergic side effects of diphenhydramine and what mnemonic-style effects they cause.

Dry eyes/blurred vision (no see), urinary retention/relaxes bladder muscle and can exacerbate BPH (no pee), dry mouth (no spit), constipation (no sh*t)

Why can diphenhydramine cause cognitive impairment in older adults?

It crosses the BBB and blocks necessary acetylcholine in the brain in older adults

What paradoxical reaction can occur in older adults and children under 6 with diphenhydramine?

Paradoxical reactions - excitability, restlessness, irritability (and rarely seizures in infants)

Are single-ingredient first-generation antihistamines safe in pregnancy?

Yes - single ingredient first-generation antihistamines are safe to use in pregnancy

Why should patients with BPH or difficulty urinating avoid diphenhydramine?

Anticholinergic effects relax the bladder muscle and can exacerbate BPH/urinary retention

Why should patients with closed-angle glaucoma avoid diphenhydramine?

Rare risk of causing acute angle-closure crisis

Why are all older adults cautioned regarding diphenhydramine (Beers List)?

It is on the Beers List due to anticholinergic burden, sedation, and cognitive impairment risk

Why should diphenhydramine not be combined with alcohol, other sedating drugs, or Alzheimer's medications?

It can increase sedation with alcohol/sedatives, and blocks the effects of Alzheimer's drugs via a pharmacodynamic drug interaction

Is diphenhydramine contraindicated in breastfeeding, and why?

Yes - contraindicated; can pass to the baby causing paradoxical effects/possible seizures, and can dry up breastmilk

What antidepressant class is diphenhydramine contraindicated with?

MAOIs (rarely used antidepressants)

What multi-ingredient product combines triprolidine and pseudoephedrine, and what is its age recommendation?

Actifed/Aprodine - approved 2+ per label but only recommended 6+ due to paradoxical reactions in children

What drug class is honey classified as for cough treatment?

Antitussive

What is the MOA of honey as a cough treatment?

Acts as a cough suppressant by coating the throat, decreasing irritation and reducing cough frequency; also has antimicrobial properties

What symptom does honey treat?

Dry cough

What side effects can honey cause?

Upset stomach or diarrhea from sugar content

What evidence supports honey's efficacy for cough?

Data supports honey as more effective than placebo (buckwheat honey formulation used in studies) and may be more effective than dextromethorphan

Is honey a good option for children under 6, and why?

Yes - may be a good alternative since data supports effectiveness in children ages 1-5 for treating nocturnal cough

What is the contraindication for honey, and why?

Avoid use in children under 1 year of age due to risk of botulism infection

Is honey safe in pregnancy and lactation?

Yes - safe

What drug class is guaifenesin (Mucinex, Robitussin)?

Protussive/expectorant

What is the MOA of guaifenesin for a productive ('chest congestion') cough?

Thins mucus and increases the volume of expectorated sputum

What is the MOA of guaifenesin for nasal congestion?

Thins nasal secretions

What type of cough is guaifenesin ineffective or minimally effective for?

Ineffective/minimally effective for a productive cough (despite being marketed as 'chest congestion' relief)

Where in the body does guaifenesin thin mucus?

Throughout the body - i.e., mucus in vaginal, nasal, and chest areas

What side effects can guaifenesin cause?

No major side effects; some patients may have GI side effects (nausea, diarrhea, stomach pain), which can be alleviated by taking with food

Why is guaifenesin considered a very safe OTC option?

No drug-drug interactions, can be used by almost all patients (healthy or with comorbidities), cannot overdose on it, and is safe in pregnancy and lactation