pharm unit 1: cough, cold, allergy

antitussives use

for cough (aka cough suppressant)

antitussives contradinications

concurrent MAOI use (antidepressant) = hypertensive crisis

antitussive MOA

blocking cough centrally and peripherally (in brain or sooths throat/chest)

antitussives central agents MOA

blocks cough center in the brain & elevates cough threshold

antitussives using central agents examples

dextromethorphan (DM)

codeine and hydrocodone (opiates)

antitussives peripheral agents MOA

numbs the local nerve endings and demulcents (sooths)

antitussives using peripheral agents examples

menthol (vicks vapor rub)

benzonatate (tessalon perles)

antitussives onset/duration

quick onset: 15-30 min w/ duration of 3-6 hours

antitussives side effects

DM: drowsiness, nausea, dizziness

Opiates: sedation, constipation

why DM vs codeine for antitussives

DM = 1st choice

- has less side effects, minimal euphoria, available OTC

cautions w/ DM (antitussive)

high doeses can cause dissociative effects like PCP

if high enough for dissociation = high enough to cause toxicity - high BP, HR, lower RR

expectorants are used for

loosening mucous from respiratory tract (thins secretions here)

contraindications of expectorants

none

expectorants MOA

increases the amount of fluid in respiratory tract - thins everything out - allows for better movement of fluids - clears out irritants and decreases mucus thickness

expectorant example

guaifenesin (duratuss, robitussin)

guaifenesin (expectorant) side effects

usually well tolerated!

nasuea, drowsiness, vomiting @ high dose

considerations w/ antitussives

-lower dose codeine gives you less respiratory depression but will still affect peds

-high dose opioids via IV can induce cough

-older gen antihistamines can be used as cough meds

considerations w/ expectorants

-not much data on efficacy w/ all ages (not recomended w/ peds)

-multisystem products = risk of overdose from duplicated ingredients

-other expecterants (not guaifenesin) can lead to acidosis, nasuea, vomiting

decongestants are used for

nasal congestion (stuffy nose)

contraindications of decongestants

used w/ MAOIs = hypertensive crisis

severe hypertension and coronary disease due to vasoconstriction

decongestants MOA

vasoconstriction = reduces hydrostatic pressure

nasal congestion is reduced as result of constriction of vessels that decrease capillary pressure, blood flow, and volume

decongestants examples (2 types)

Direct agonists - sudafed PE , afrin

indirect agonists - sudafed

direct agonist decongestant examples

phenylephrine (sudafed PE, dimetapp)

oxymetazoline (afrin)

indirect agonist decongestant example

pseudoephedrine (sudafed)

decongestant onset/duration

oral onset: 30 min w/ 4-6 hr duration

topical agents: faster onset of action w/ fewer systemic effects

decongestant side effects

CNS stimulation = agitation (hyperstimulated) , anxiety, insomnia

**Increased heart rate and palpitations

-rebound nasal congestion

-dry mouth

-sweating

-local irritation/nostril burning

considerations w/ decongestants

Rhinitis medicamentosa = rebound nasal congestion w/ chronic spray use

pseudoephedrine has precurser ingridents to meth so it is behind the counter and monitered how much you buy

H1 histamine antagonists are used for

allergic rhinitis, urticaria (itchy rashes) , nasal symptoms from common cold, nausea (1st gen)

contraindications of H1 antagonists

none

H1 histamine antagonists MOA

blocks allergic response meditated by histamine - blocks histamine receptor from releasing allergy cascade = helps w/ allergy symptoms

anticholinergic effects w/ 1st gens = used for nausea

1st gen H1 antagonists examples

diphenhydramine (benadryl)

chlorpheniramine (chlortrimeton)

hydroxzyine (atarax)

cyproheptadine (periactin) - common in kids

2nd gen H1 antagonists examples

Loratadine (claritin)

cetirizine (zyrtec)

fexofenadine (allegra)

considerations w/ antihistamines

*sedation w/ 1st gen mostly

-not used for acute anaphylactic reactions bc it can't control hypotension & bronchoconstriction

other use of H1 antagonists

for insomnia bc of sedative effects

doxeoin

a TCA antidepressant but has potent antihistamine activity

mast cell stabilizers are used for

conditions w/ allergy component and adjuct therapy (can't be used alone/must be used prior to allergen exposure)

-ashtma, rhinitis, conjunctivitis, systemic mastocytosis

contraindications of mast cell stabilizers

none

mast cell stabilizers MOA

prevents degranulation of mast cells = blocks release of proinflammatory factors

mast cell stabilizers example

cromolyn sodium (nasal crom)

side effects of cromolyn sodium (mast cell stabilizer)

well tolerated but can get cough from throat irritation and nose irritation bc it's inhaled

considerations for cormolyn sodium (mast cell stabilizer)

doesn't give bronchodialation = NOT useful for ashtma attack or allergy symptoms that have already started

leukotriene receptor antagonist (LTRAs) are used for

prevention of persistent asthma (but not 1st line)

exercise induced asthma/bronchospasm

allergic rhinitis

leukotriene receptor antagonist contraindication

acute liver disease/ any impaired liver functioning

not for asthma - prevention only

leukotriene receptor antagonist MOA

inhibits enzyme responsible for producing inflammation response to leukotriene = reduces bronchoconstriction and decreases inflammation

leukotriene receptior antagonist example

montelukast (singulair)

intranasal steroids are used for

allergic rhinitis - congestion, sneeze, itchy, rhinorrhea

nasal congestion - good alternative for pts who cannot use decongestants bc of hypertension/palpitations

contraindications of intranasal steroids

hypersensitivity, but usually well tolerated in all ages

intranasal steroid MOA

inhibits cells that contribute to inflammation (mast cells, eosinophils, basophils, lymphocytes, macrophages)

intranasal steroid examples

fluticasone (flonase/veramyst)

mometasone (nasonex)

considerations w/ intranasal steroids

minimal systemic absorption = not bad side effects

slower response than antihistamines and requires continuous dosing - especially when using for rebound congestion