Acrivastine + Pseudoephedrine

Oral
Allergic rhinitis

CrCl ≤48 mL/min: Contraindicated.

No dosage adjustment needed.

Hypersensitivity to triprolidine. Severe HTN or coronary artery disease; renal impairment (CrCl ≤48 mL/min). Concomitant use w/ pseudoephedrine-containing products and MAOIs w/ or w/in 14 days.

Patients w/ heart disease, HTN, hyperthyroidism, diabetes, elevated intra-ocular pressure and prostatic enlargement. Elderly. Pregnancy and lactation.

CNS depression, sleep disturbance, hallucinations, skin rashes, w/ or w/o irritation.

PO: B

Symptoms: Restlessness, convulsions, irritability, palpitations, tremor, HTN and difficulty w/ micturition. Management: Emptying the stomach by gastric lavage, or use acid diuresis or dialysis to accelerate the elimination of pseudoephedrine.

May increase BP w/ antihypertensive agents, TCA or other sympathomimetic agents (e.g. decongestants, appetite suppressants and amfetamine-like psychostimulants). May reverse the antihypertensive effect of α- and β-adrenergic blockers, betanidine, guanethidine, bretylium, methyldopa and debrisoquine.
Potentially Fatal: Increased BP w/ pseudoephedrine-containing products and MAOIs.

Pseudoephedrine may cause false-positive result w/ urine detection of amfetamine.

Description:
Mechanism of Action: Acrivastine is a non-sedating antihistamine that is structurally related to triprolidine. It provides symptomatic relief by competitively blocking H₂-receptor. Pseudoephedrine is both an α-and β-adrenergic receptor agonist. It causes vasoconstriction via direct stimulation of α-adrenergic receptors of the resp mucosa. It also directly stimulates β-adrenergic receptors causing bronchial relaxation, increased heart rate and contractility.
Pharmacokinetics:
Absorption: Both are readily absorbed from the GI tract. Time to peak plasma concentration: Acrivastine: Approx 1.3 hr; Pseudoephedrine: Approx 2 hr.
Distribution: Pseudoephedrine may cross the placenta, enter CSF and distributed into breast milk. Volume of distribution: Acrivastine: Approx 0.5-0.8 L/kg; Pseudoephedrine: 2.64-3.51 L/kg. Plasma protein binding: Acrivastine: Approx 50% (mainly to albumin).
Metabolism: Acrivastine: Minimal hepatic metabolism. Pseudoephedrine: Undergoes N-demethylation to norpseudoephedrine (active metabolite).
Excretion: Acrivastine: Via urine (84%); faeces (13%). Pseudoephedrine: Via urine (43-96% as unchanged drug; 1-6% as norpseudoephedrine).

Store between 15-25°C.

Antihistamines & Antiallergics

Anon. Acrivastine and Pseudoephedrine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 05/09/2013.

Anon. Pseudoephedrine. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 05/09/2013.

Anon. Pseudoephedrine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 05/09/2013.

Buckingham R (ed). Acrivastine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 05/09/2013.

Buckingham R (ed). Pseudoephedrine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 05/09/2013.

McEvoy GK, Snow EK, Miller J et al (eds). Acrivastine. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 05/09/2013.