Skip to main content

Drug Interactions between ConRx PM and Topamax

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

diphenhydrAMINE topiramate

Applies to: ConRx PM (acetaminophen / diphenhydramine) and Topamax (topiramate)

MONITOR CLOSELY: Certain drugs such as carbonic anhydrase inhibitors and drugs with anticholinergic activity (e.g., antihistamines, antispasmodics, neuroleptics, phenothiazines, skeletal muscle relaxants, tricyclic antidepressants, disopyramide) may potentiate the risk of oligohidrosis and hyperthermia associated occasionally with the use of topiramate, particularly in pediatric patients. These agents may alter electrolyte and fluid balance (carbonic anhydrase inhibition), inhibit peripheral sweating mechanisms (anticholinergic effect), and/or interfere with core body temperature regulation in the hypothalamus (neuroleptics and phenothiazines), resulting in the inability to adjust to temperature changes, especially in hot weather. Also, agents with anticholinergic activity frequently cause drowsiness and other central nervous system-depressant effects, which may be additively or synergistically increased in patients also treated with topiramate.

MANAGEMENT: Caution is advised when topiramate is prescribed with other drugs that predispose patients to heat-related disorders, including carbonic anhydrase inhibitors and drugs with anticholinergic activity. Patients, particularly pediatric patients, should be monitored closely for evidence of decreased sweating and increased body temperature, especially in warm or hot weather. Proper hydration before and during vigorous activities or exposure to warm temperatures is recommended. Patients (or their guardians or caregivers) should contact their physician immediately if they are not sweating as usual, with or without a fever. Ambulatory patients treated with topiramate and agents with anticholinergic activity should also be made aware of the possibility of additive CNS effects (e.g., drowsiness, dizziness, lightheadedness, confusion) and counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References

  1. "Product Information. Topamax (topiramate)." Ortho McNeil Pharmaceutical PROD (2001):

Switch to consumer interaction data

Drug and food interactions

Major

acetaminophen food

Applies to: ConRx PM (acetaminophen / diphenhydramine)

GENERALLY AVOID: Chronic, excessive consumption of alcohol may increase the risk of acetaminophen-induced hepatotoxicity, which has included rare cases of fatal hepatitis and frank hepatic failure requiring liver transplantation. The proposed mechanism is induction of hepatic microsomal enzymes during chronic alcohol use, which may result in accelerated metabolism of acetaminophen and increased production of potentially hepatotoxic metabolites.

MANAGEMENT: In general, chronic alcoholics should avoid regular or excessive use of acetaminophen. Alternative analgesic/antipyretic therapy may be appropriate in patients who consume three or more alcoholic drinks per day. However, if acetaminophen is used, these patients should be cautioned not to exceed the recommended dosage (maximum 4 g/day in adults and children 12 years of age or older).

References

  1. Kaysen GA, Pond SM, Roper MH, Menke DJ, Marrama MA "Combined hepatic and renal injury in alcoholics during therapeutic use of acetaminophen." Arch Intern Med 145 (1985): 2019-23
  2. O'Dell JR, Zetterman RK, Burnett DA "Centrilobular hepatic fibrosis following acetaminophen-induced hepatic necrosis in an alcoholic." JAMA 255 (1986): 2636-7
  3. Seeff LB, Cuccherini BA, Zimmerman HJ, Adler E, Benjamin SB "Acetaminophen hepatotoxicity in alcoholics." Ann Intern Med 104 (1986): 399-404
  4. Thummel KE, Slattery JT, Nelson SD "Mechanism by which ethanol diminishes the hepatotoxicity of acetaminophen." J Pharmacol Exp Ther 245 (1988): 129-36
  5. McClain CJ, Kromhout JP, Peterson FJ, Holtzman JL "Potentiation of acetaminophen hepatotoxicity by alcohol." JAMA 244 (1980): 251-3
  6. Kartsonis A, Reddy KR, Schiff ER "Alcohol, acetaminophen, and hepatic necrosis." Ann Intern Med 105 (1986): 138-9
  7. Prescott LF, Critchley JA "Drug interactions affecting analgesic toxicity." Am J Med 75 (1983): 113-6
  8. "Product Information. Tylenol (acetaminophen)." McNeil Pharmaceutical PROD (2002):
  9. Whitcomb DC, Block GD "Association of acetaminopphen hepatotoxicity with fasting and ethanol use." JAMA 272 (1994): 1845-50
  10. Bonkovsky HL "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA 274 (1995): 301
  11. Nelson EB, Temple AR "Acetaminophen hepatotoxicity, fasting, and ethanol." JAMA 274 (1995): 301
  12. Zimmerman HJ, Maddrey WC "Acetaminophen (paracetamol) hepatotoxicity with regular intake of alcohol: analysis of instances of therapeutic misadventure." Hepatology 22 (1995): 767-73
View all 12 references

Switch to consumer interaction data

Moderate

diphenhydrAMINE food

Applies to: ConRx PM (acetaminophen / diphenhydramine)

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.

References

  1. Linnoila M "Drug effects on psychomotor skills related to driving: interaction of atropine, glycopyrrhonium and alcohol." Eur J Clin Pharmacol 6 (1973): 107-12

Switch to consumer interaction data

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer