From the Guidelines
Meclizine and Dramamine (Dimenhydrinate) are both used to treat nausea and vomiting, but they have different dosing recommendations: Meclizine is typically given at a dose of 12.5–25 mg tid, while Dimenhydrinate is given at a dose of 25–50 mg tid 1.
Key Differences
- Dose: The dose of Meclizine is lower than that of Dimenhydrinate, with a recommended dose of 12.5–25 mg tid compared to 25–50 mg tid for Dimenhydrinate 1.
- Indication: Both medications are used to treat nausea and vomiting, but Meclizine is also used for vertigo and motion sickness, while Dimenhydrinate is primarily used for motion sickness and nausea.
Mechanism of Action
Both Meclizine and Dimenhydrinate are antihistamines that work by blocking the action of histamine in the brain, which helps to relieve nausea and vomiting. However, Meclizine is a piperazine derivative, while Dimenhydrinate is a diphenhydramine derivative, which may affect their side effect profiles and efficacy.
Clinical Use
In clinical practice, the choice between Meclizine and Dimenhydrinate may depend on the specific patient population and the severity of their symptoms. For example, Meclizine may be preferred for patients with vertigo or motion sickness, while Dimenhydrinate may be preferred for patients with more severe nausea and vomiting. Ultimately, the decision should be based on individual patient needs and medical history.
From the FDA Drug Label
Meclizine hydrochloride, USP a histamine (H1) receptor antagonist, is a white to slight yellowish crystalline powder. Dimenhydrinate, an anti-nauseant/antiemetic, is the 8-chlorotheophylline salt of diphenhydramine.
The main difference between Meclizine and Dramamine (Dimenhydrinate) is that:
- Meclizine is a histamine (H1) receptor antagonist
- Dimenhydrinate is an anti-nauseant/antiemetic and the 8-chlorotheophylline salt of diphenhydramine 2 3 Key differences include their:
- Active ingredients: Meclizine vs Diphenhydramine
- Mechanisms of action: Histamine (H1) receptor antagonist vs anti-nauseant/antiemetic 2 3
From the Research
Difference between Meclizine and Dramamine (Dimenhydrinate)
- Meclizine and Dramamine (Dimenhydrinate) are both used to prevent and treat motion sickness symptoms, but they have different mechanisms of action and effects on the body 4.
- Dramamine (Dimenhydrinate) affects the central nervous system (CNS), while Meclizine (Marezine) affects the stomach directly, making Meclizine more effective in preventing gastric dysrhythmias and gastrointestinal (GI) symptoms 4.
- Both drugs are effective in preventing overall subjective symptoms of motion sickness, but Meclizine is associated with significantly less drowsiness than Dramamine 4.
Comparison of Efficacy and Side Effects
- A study comparing two formulations of Dimenhydrinate found that a slow release formulation had less sedative effects and less impact on vigilance and CNS performance compared to a fast release formulation 5.
- Another study found that prophylactic administration of Dimenhydrinate is as effective as Ondansetron in preventing postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic cholecystectomy, and is a more cost-effective option 6.
- Dimenhydrinate has been reported to have abuse potential, with users experiencing euphoric sensations and hallucinations, and it interacts with other neurotransmitter systems, including those using acetylcholine, serotonin, and dopamine 7.
Effects on Nystagmic Responses
- A study examining the effects of antimotion sickness drugs on nystagmic responses found that Dimenhydrinate reduced optokinetic nystagmus and interfered with visual fixation during motion, particularly at higher dose levels 8.
- The study also found that the effect of a drug on nystagmus may be a poor indicator of its value in preventing motion sickness, and that assessments of antimotion sickness drugs should include the ability to maintain visual fixation during motion as a possible adverse side effect 8.