What are the medical indications and usage guidelines for Gravol (dimenhydrinate) in patients with various medical conditions, including pediatric and geriatric populations?

Medical Indications for Gravol (Dimenhydrinate)

Gravol (dimenhydrinate) is FDA-approved for the prevention and treatment of nausea, vomiting, and vertigo associated with motion sickness, and serves as first-line pharmacologic antiemetic therapy for various conditions including pregnancy-related nausea, gastroparesis, and vestibular disorders. 1, 2

Primary FDA-Approved Indications

• Motion sickness: Prevention and treatment of nausea, vomiting, or vertigo 1
• General nausea and vomiting: First-line pharmacologic antiemetic therapy at doses of 25-50 mg three times daily 2
• Refractory gastroparesis: Recommended at 25-50 mg three times daily when other treatments fail 2

Pregnancy-Related Use

Dimenhydrinate is considered safe and recommended by ACOG as first-line pharmacologic therapy for persistent nausea and vomiting of pregnancy (NVP) when non-pharmacologic approaches prove ineffective. 2

• Use H1-receptor antagonists like dimenhydrinate when dietary modifications, ginger, and vitamin B6 fail to control symptoms 2
• ACOG specifically endorses dimenhydrinate among antihistamines for this indication 2

Vestibular Disorders

• Ménière's disease: Used to manage acute vertigo symptoms 2

Pediatric Considerations

When to Use in Children

• May be considered for acute gastroenteritis-related vomiting, but only as adjunct to—never as substitute for—fluid and electrolyte therapy 2
• Appears safe for pediatric use based on available safety data 3

Critical Pediatric Contraindications

• Absolutely contraindicated in neonates due to benzyl alcohol content, which causes fatal "Gasping Syndrome" in premature infants and low birth weight babies 1
• Do not give to children under 18 years with acute diarrhea 2
• Physicians must identify the underlying cause of vomiting before prescribing to ensure appropriateness 3

Dosing Guidelines

Adults

• Standard dose: 50 mg intramuscularly or intravenously every 4 hours as needed 1
• Higher dose: 100 mg every 4 hours may be used when drowsiness is acceptable or desirable 1
• For IV administration: Dilute each 50 mg in 10 mL of 0.9% sodium chloride and inject over 2 minutes 1
• Duration of action: Approximately 4 hours per dose 1

Pediatric (when appropriate)

• Intramuscular dose: 1.25 mg/kg body weight OR 37.5 mg/m² body surface area, four times daily 1
• Maximum daily dose: 300 mg 1

Important Safety Warnings

Absolute Contraindications

• Neonates (due to benzyl alcohol content causing fatal gasping syndrome) 1
• History of hypersensitivity to dimenhydrinate, diphenhydramine, or 8-chlorotheophylline 1

Abuse Potential

Clinicians must be aware that dimenhydrinate has significant abuse liability. 4, 5

• Abused for euphoric sensations, hallucinations, and anxiolytic effects at supratherapeutic doses 4, 5
• Case reports document intravenous abuse of up to 2400 mg/day 5
• Withdrawal symptoms include severe nausea, vomiting, sedation, headaches, dizziness, anxiety, and muscle stiffness 5
• Chronic high-dose abuse may contribute to early cognitive impairment and irreversible deficits 6

Cognitive Concerns

• Anticholinergic properties raise concerns about dementia risk with chronic use, particularly in elderly populations 6
• Screen for aberrant use patterns in patients requesting frequent refills 5

Clinical Pearls

• Cost-effectiveness: Dimenhydrinate ($2.50/dose) is as effective as ondansetron ($17/dose) for preventing postoperative nausea and vomiting after laparoscopic cholecystectomy, making it the preferred agent from a cost perspective 7
• Drug interactions: Verify compatibility with other medications before prescribing, especially in polypharmacy situations 3
• Drowsiness: Expect some degree of sedation; this can be therapeutic in certain clinical contexts 1