Chlorpheniramine Maleate
Indications
Chlorpheniramine Maleate is used for:
Urticaria, Sneezing, Watery eyes, Allergic conditions, Anaphylactic shock, Rhinitis, Itching
Adult Dose
Oral
Adult: 4 mg every 4-6 hr. Max: 24 mg daily.
Parenteral
Adjunct in the emergency treatment of anaphylactic shock
Adult: 10-20 mg IM, SC, or slow IV inj over 1 min. Max dose: 40 mg daily.
Child Dose
Oral
Child: 1-2 yr: 1 mg bid,
2-5 yr: 1 mg every 4-6 hr,
6-12 yr: 2 mg every 4-6 hr.
Max: 6 mg daily (1-5 yr); 12 mg daily (6-12 yr).
Parenteral
Adjunct in the emergency treatment of anaphylactic shock
Child: 87.5 mcg/kg SC 4 times daily
Renal Dose
Administration
Contra Indications
Hypersensitivity, Neonates.
Precautions
Elderly, pylori duodenal obstruction, angle-closure glaucoma, urinary retention, prostatic hyperplasia, epilepsy, renal and hepatic impairment. May affect performance of skilled tasks. BPH, bladder neck obstruction, hypertension. Pregnancy, lactation.
Pregnancy-Lactation
Pregnancy
Antihistamine exposure in first trimester not reported to be associated with increased risk of malformations; animal studies not reported; there are no controlled data in human pregnancy; only recommended for use during pregnancy when benefit outweighs risk
Lactation
Excretion into human milk; the manufacturer recommends that caution be used when administering chlorpheniramine to nursing women; infants should be monitored for irritability or drowsiness; antihistamines may temporarily decrease maternal serum prolactin concentrations when administered prior to nursing infant for the first time
Interactions
Potentiates sedative effect of psychotropic drugs e.g. barbiturates, hypnotics, opioid analgesics, anxiolytics and antipsychotics. Interaction with alcohol could be dangerous (sedation/excitation).
Adverse Effects
Side effects of Chlorpheniramine Maleate :
CNS depression, sedation, drowsiness, lassitude, dizziness. GI upsets, anorexia, or increased appetite, epigastric pain, blurring of vision, dysuria, dryness of mouth, tightness in chest, hypotension, muscular weakness, tinnitus, euphoria, headache, paradoxical CNS stimulation.
Potentially Fatal: CV collapse and respiratory failure.
Mechanism of Action
Chlorphenamine is an H1-receptor antagonist which competetively blocks H1-receptor sites on tissues.