Page 163 - 2025 Ranger Medic Handbook

CETIRIZINE (ZYRTEC)
Class: ENT agent – H 1 -receptor antagonist; nonsedating antihistamine
Action: Potent H 1 -receptor antagonist and antihistamine; low lipophilicity and H 1 - receptor selectivity and thus no
significant anticholinergic or CNS activity; reduces local and systemic effects of histamine release
Dose: 5–10mg PO qd
Indications: Seasonal and perennial allergic rhinitis and chronic idiopathic urticaria
Contraindications: H 1 -receptor antihistamine hypersensitivity; pregnancy category may use during pregnancy and
caution advised while breastfeeding
Adverse/Side-effects: Constipation, diarrhea, dry mouth; drowsiness, sedation, headache, depression
Interactions: Theophylline may decrease clearance leading to toxicity; do not use in combination with OTC
antihistamines
Mission Impact: GROUNDING medication for personnel on flight status

CIMETIDINE (TAGAMET) SECTION 4
Class: GI agent – antisecretory H 2 -receptor antagonist
Action: Antihistamine with high selectivity for reversible competitive inhibition of histamine H 2 -receptors on parietal
cells of the stomach (minimal effect on H 1 -receptors) and thus decreases gastric acid secretion, raises the pH of the
stomach, and indirectly reduces pepsin secretion
Dose: Oral: 300mg QID or 800mg at bedtime or 400mg bid for up to 8 weeks
Indications: For treatment of duodenal/gastric ulcer, prevention of ulcer recurrence, gastroesophageal reflux, chronic
urticaria, acetaminophen toxicity
Contraindications: H 2 -receptor antagonist hypersensitivity; pregnancy category may use during pregnancy and while
breastfeeding
Adverse/Side-effects: Fever, cardiac arrhythmias and cardiac arrest after rapid IV bolus; diarrhea, constipation,
abdominal discomfort; increased prothrombin time, neutropenia, thrombocytopenia, aplastic anemia, hypospermia,
exacerbation of preexisting arthritis; drowsiness, dizziness, light-headedness, depression, headache, reversible con-
fusion states, paranoid psychosis; rash, Stevens-Johnson syndrome, reversible alopecia, gynecomastia, galactor-
rhea, reversible impotence
Interactions: Decreases hepatic metabolism of warfarin, phenobarbital, phenytoin, diazepam, propranolol, lidocaine,
theophylline, thus increasing their activity and toxicity; antacids may decrease absorption

2025 RANGER MEDIC HANDBOOK 149