Can Dramamine (Dimenhydrinate) cause oliguric crisis (decreased urine output)?

Dimenhydrinate and Oliguric Crisis

Dimenhydrinate (Dramamine) does not directly cause oliguric crisis based on available evidence. The FDA drug label for dimenhydrinate does not list oliguria or decreased urine output as known adverse effects 1.

Understanding Dimenhydrinate's Side Effects

Dimenhydrinate (Dramamine) is an antihistamine commonly used for motion sickness. According to the FDA drug label, the most common adverse reactions include:

• Drowsiness
• Dizziness
• Dry mouth, nose, and throat
• Blurred vision
• Difficult or painful urination (but not decreased urine output)
• Headache
• Nervousness or restlessness
• Tachycardia
• Epigastric distress 1

While dimenhydrinate can cause "difficult or painful urination," this refers to dysuria rather than oliguria (decreased urine output).

Understanding Oliguria

Oliguria is defined as urine output less than 0.5 mL/kg/hour for at least 6 hours, or less than 400-500 mL/day in adults 2. It can represent either:

• An appropriate physiological response to volume depletion
• A pathological condition indicating kidney dysfunction 2

Causes of Oliguria

Oliguria commonly results from:

1. Prerenal causes (decreased renal perfusion):

   • Hypovolemia
   • Heart failure
   • Sepsis
   • Medications that affect renal blood flow 3

2. Intrinsic renal causes:

   • Acute tubular necrosis
   • Glomerulonephritis
   • Interstitial nephritis 3

3. Postrenal causes:

   • Urinary tract obstruction 3

Medications Associated with Oliguria

Medications that can cause or contribute to oliguria include:

• NSAIDs
• ACE inhibitors
• ARBs
• Calcineurin inhibitors
• Certain antibiotics (aminoglycosides)
• Contrast media

Dimenhydrinate is notably absent from this list of medications known to cause oliguria.

Management of Oliguria

If a patient develops oliguria while taking dimenhydrinate:

1. Assess volume status - Determine if the patient is hypovolemic or normovolemic 3
2. Check laboratory values - Evaluate BUN, creatinine, electrolytes, and urinary sodium 3
3. Consider other causes - Look for other medications or conditions that could be responsible
4. Fluid challenge - In hypovolemic patients, a fluid bolus may resolve oliguria 3
5. Discontinue potential nephrotoxic medications - If necessary

Conclusion

While dimenhydrinate can cause various side effects including urinary symptoms such as difficult or painful urination, there is no evidence in the medical literature or FDA drug labeling that it directly causes oliguric crisis or decreased urine output. If oliguria develops in a patient taking dimenhydrinate, clinicians should investigate other more common causes of decreased urine output rather than attributing it to dimenhydrinate.