Skip to main content

Drug Interactions between mefloquine and Quadrinal

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

Edit list (add/remove drugs)

Interactions between your drugs

Major

mefloquine PHENobarbital

Applies to: mefloquine and Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

GENERALLY AVOID: Mefloquine may increase the risk of seizures and decrease the effectiveness of anticonvulsant drugs in patients with epilepsy. The use of mefloquine alone and in combination with other related antimalarial agents (e.g., quinine, quinidine, chloroquine) has been associated with convulsions in some patients. Coadministration of mefloquine with certain anticonvulsant medications may also result in reduced seizure control by lowering the plasma levels of the anticonvulsant. In one case report, a patient with a seizure disorder previously well controlled on valproic acid and carbamazepine experienced several seizure episodes after taking mefloquine (250 mg weekly) for malaria prophylaxis. A subsequent kinetics study performed on the patient revealed a significant reduction in sodium valproate half-life (5.65 hours vs. reported normal of 8 to 20 hours) and no change in carbamazepine half-life. The author suggested that mefloquine be administered to epileptic patients with caution, particularly if being treated with sodium valproate. Additional clinical data with other antiepileptics are unavailable.

MANAGEMENT: According to the product labeling, mefloquine may precipitate convulsions in patients with a history of seizure disorder and should not be used for malaria prophylaxis in such patients. If mefloquine administration is required for curative treatment of malaria, anticonvulsant blood levels should be closely monitored and the anticonvulsant dosage adjusted accordingly as needed. Patients should be advised to notify their physician if they experience a loss of seizure control.

MONITOR CLOSELY: Coadministration with potent inducers of CYP450 3A4 may significantly decrease the plasma concentrations of mefloquine, which is primarily metabolized by the isoenzyme. In seven healthy, nonsmoking male volunteers, administration of a single 500 mg oral dose of mefloquine on day 7 of treatment with the potent CYP450 3A4 inducer rifampin (600 mg orally once daily on days 1 through 7, followed by 600 mg twice weekly on days 8 through 56) decreased mean mefloquine peak plasma concentration (Cmax) and systemic exposure (AUC) by 19% and 68%, respectively, compared to mefloquine administered alone. The mean elimination half-life of mefloquine was also decreased by 63% (from 305 to 113 hours) in the presence of rifampin, while mean apparent oral clearance increased by 281%.

MANAGEMENT: The possibility of diminished antimalarial efficacy should be considered when mefloquine is used in combination with potent CYP450 3A4 inducers. Alternative agents with minimal or less enzyme induction potential are recommended when possible to avoid the risk of therapeutic failure, particularly in the treatment of acute malaria infections.

References

  1. Singh K, Shanks GD, Wilde H (1991) "Seizures after mefloquine." Ann Intern Med, 114, p. 994
  2. Weinke T, Trautmann M, Held T, et al. (1991) "Neuropsychiatric side effects after the use of mefloquine." Am J Trop Med Hyg, 45, p. 86-91
  3. Bem JL, Kerr L, Stuerchler D (1992) "Mefloquine prophylaxis: an overview of spontaneous reports of severe psychiatric reactions and convulsions." J Trop Med Hyg, 95, p. 167-79
  4. Jallon P (1988) "Use of mefloquine in epileptic patients." J Neurol Neurosurg Psychiatry, 51, p. 732
  5. (2021) "Product Information. Mefloquine Hydrochloride (mefloquine)." Hikma USA (formerly West-Ward Pharmaceutical Corporation)
  6. Ries S, Pohlmanneden B (1993) "Seizures during malaria prophylaxis with mefloquine." Dtsch Med Wochenschr, 118, p. 1911-2
  7. Ruff TA, Sherwen SJ, Donnan GA (1994) "Seizure associated with mefloquine for malaria prophylaxis." Med J Aust, 161, p. 453
  8. Pous E, Gascon J, Obach J, Corachan M (1995) "Mefloquine-induced grand mal seizure during malaria chemoprophylaxis in a non-epileptic subject." Trans R Soc Trop Med Hyg, 89, p. 434
  9. Potasman I, Juven Y, Weller B, Schwartz E (2002) "Does mefloquine prophylaxis affect electroencephalographic patterns?" Am J Med, 112, p. 147-9
  10. Jimenez-Huete A, Gil-Nagel A, Franch O (2002) "Multifocal myoclonus associated with mefloquine chemoprophylaxis." Clin Neuropharmacol, 25, p. 243
  11. Ridtitid W, Wongnawa M, Mahatthanatrakul W, Chaipol P, Sunbhanich M (2000) "Effect of rifampin on plasma concentrations of mefloquine in healthy volunteers." J Pharm Pharmacol, 52, p. 1265-9
  12. (2022) "Product Information. Lariam (mefloquine)." Pharmaco Australia Ltd
  13. (2017) "Product Information. Mefloquine (mefloquine)." AA Pharma Inc
  14. (2022) "Product Information. Lariam (mefloquine)." Neon Healthcare Ltd
View all 14 references

Switch to consumer interaction data

Moderate

theophylline PHENobarbital

Applies to: Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline) and Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

MONITOR: Barbiturates may decrease serum levels and therapeutic effects of the methylxanthines. The mechanism is barbiturate induction of CYP450 3A4 and 1A2 hepatic metabolism of methylxanthines.

MANAGEMENT: Close observation for clinical and laboratory evidence of decreased methylxanthine effect is indicated if these drugs must be used together. Patients should be advised to notify their physician if they experience a worsening of their respiratory symptoms.

References

  1. Upton RA (1991) "Pharmacokinetic interactions between theophylline and other medication (Part I)." Clin Pharmacokinet, 20, p. 66-80
  2. Bukowskyj M, Nakatsu K, Munt PW (1984) "Theophylline reassessed." Ann Intern Med, 101, p. 63-73
  3. Landay RA, Gonzalez MA, Taylor JC (1978) "Effect of phenobarbital on theophylline disposition." J Allergy Clin Immunol, 62, p. 27-9
  4. Dahlqvist R, Steiner E, Koike Y, von Bahr C, Lind M, Billing B (1989) "Induction of theophylline metabolism by pentobarbital." Ther Drug Monit, 11, p. 408-10
View all 4 references

Switch to consumer interaction data

Minor

theophylline ePHEDrine

Applies to: Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline) and Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

Ephedrine-methylxanthine combinations are used for the treatment of asthma but the efficacy of the combination has been questioned. This combination may lead to increased xanthine side effects. The mechanism is unknown, but may be related to synergistic pharmacologic effects. Patients using this combination should be closely monitored for side effects such as nausea, vomiting, tachycardia, nervousness, or insomnia. If side effects are noted, the dosage of the xanthine may need to be decreased.

References

  1. Weinberger M, Bronsky E, Bensch GW, Bock GN, Yecies JJ (1975) "Interaction of ephedrine and theophylline." Clin Pharmacol Ther, 17, p. 585-92
  2. Sims JA, doPico GA, Reed CE (1978) "Bronchodilating effect of oral theophylline-ephedrine combination." J Allergy Clin Immunol, 62, p. 15-21
  3. Tinkelman DG, Avner SE (1977) "Ephedrine therapy in asthmatic children. Clinical tolerance and absence of side effects." JAMA, 237, p. 553-7
  4. Weinberger MM, Brousky EA (1974) "Evaluation of oral bronchodilator therapy in asthmatic children: bronchodilators in asthmatic children." J Pediatr, 84, p. 421-7
  5. Badiei B, Faciane J, Sly M (1975) "Effect of throphylline, ephedrine and theri combination upon exercise-induced airway obstruction." Ann Allergy, 35, p. 32-6
View all 5 references

Switch to consumer interaction data

Drug and food interactions

Major

PHENobarbital food

Applies to: Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.

MANAGEMENT: The combination of ethanol and barbiturates should be avoided.

References

  1. Gupta RC, Kofoed J (1966) "Toxological statistics for barbiturates, other sedatives, and tranquilizers in Ontario: a 10-year survey." Can Med Assoc J, 94, p. 863-5
  2. Misra PS, Lefevre A, Ishii H, Rubin E, Lieber CS (1971) "Increase of ethanol, meprobamate and pentobarbital metabolism after chronic ethanol administration in man and in rats." Am J Med, 51, p. 346-51
  3. Saario I, Linnoila M (1976) "Effect of subacute treatment with hypnotics, alone or in combination with alcohol, on psychomotor skills related to driving." Acta Pharmacol Toxicol (Copenh), 38, p. 382-92
  4. Stead AH, Moffat AC (1983) "Quantification of the interaction between barbiturates and alcohol and interpretation of fatal blood concentrations." Hum Toxicol, 2, p. 5-14
  5. Seixas FA (1979) "Drug/alcohol interactions: avert potential dangers." Geriatrics, 34, p. 89-102
View all 5 references

Switch to consumer interaction data

Moderate

theophylline food

Applies to: Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

GENERALLY AVOID: Coadministration with caffeine may increase the serum concentrations of theophylline. The proposed mechanism involves competitive inhibition of theophylline metabolism via CYP450 1A2, as well as metabolic conversion of caffeine to theophylline in vivo and saturation of theophylline metabolism at higher serum concentrations. In six healthy male volunteers (all smokers), serum concentrations of theophylline (administered as aminophylline 400 mg single oral dose) were significantly higher following consumption of caffeine (2 to 7 cups of instant coffee over 24 hours, equivalent to approximately 120 to 630 mg of caffeine) than after caffeine deprivation for 48 hours. Caffeine consumption also increased the apparent elimination half-life of theophylline by an average of 32% and reduced its total body clearance by 23%. In another study, steady-state concentration and area under the concentration-time curve of theophylline (1200 mg intravenously over 24 hours) increased by 23% and 40%, respectively, in eight healthy volunteers following administration of caffeine (300 mg orally three times a day).

MANAGEMENT: Given the narrow therapeutic index of theophylline, patients should limit or avoid significant fluctuations in their intake of pharmacologic as well as dietary caffeine.

ADJUST DOSING INTERVAL: Administration of theophylline with continuous enteral nutrition may reduce the serum levels or the rate of absorption of theophylline. The mechanism has not been reported. In one case, theophylline levels decreased by 53% in a patient receiving continuous nasogastric tube feedings and occurred with both theophylline tablet and liquid formulations, but not with intravenous aminophylline.

MANAGEMENT: When administered to patients receiving continuous enteral nutrition , some experts recommend that the tube feeding should be interrupted for at least 1 hour before and 1 hour after the dose of theophylline is given; rapid-release formulations are preferable, and theophylline levels should be monitored.

References

  1. Jonkman JH, Sollie FA, Sauter R, Steinijans VW (1991) "The influence of caffeine on the steady-state pharmacokinetics of theophylline." Clin Pharmacol Ther, 49, p. 248-55
  2. Sato J, Nakata H, Owada E, Kikuta T, Umetsu M, Ito K (1993) "Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects." Eur J Clin Pharmacol, 44, p. 295-8
  3. Wohlt PD, Zheng L, Gunderson S, Balzar SA, Johnson BD, Fish JT (2009) "Recommendations for the use of medications with continuous enteral nutrition." Am J Health Syst Pharm, 66, p. 1438-67

Switch to consumer interaction data

Moderate

mefloquine food

Applies to: mefloquine

ADJUST DOSING INTERVAL: Food enhances the oral absorption and bioavailability of mefloquine. The proposed mechanism is increased drug solubility in the presence of food. In 20 healthy volunteers, administration of a single 750 mg oral dose of mefloquine 30 minutes following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of mefloquine by 73% and 40%, respectively, compared to administration in the fasting state. The Cmax and AUC of the carboxylic acid metabolite were also increased by 35% and 33%, respectively, compared to fasting. In addition, the time to reach peak plasma concentration (Tmax) of mefloquine was significantly shorter after food intake (17 hours) than in the fasting state (36 hours). There was no difference in the elimination half-life of mefloquine and metabolite, or the Tmax for the metabolite.

MANAGEMENT: To ensure maximal oral absorption, mefloquine should be administered immediately after a meal with at least 8 ounces of water.

References

  1. (2021) "Product Information. Mefloquine Hydrochloride (mefloquine)." Hikma USA (formerly West-Ward Pharmaceutical Corporation)
  2. Schmidt LE, Dalhoff K (2002) "Food-drug interactions." Drugs, 62, p. 1481-502

Switch to consumer interaction data

Moderate

theophylline food

Applies to: Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

GENERALLY AVOID: Coadministration with caffeine may increase the serum concentrations of theophylline. The proposed mechanism involves competitive inhibition of theophylline metabolism via CYP450 1A2, as well as metabolic conversion of caffeine to theophylline in vivo and saturation of theophylline metabolism at higher serum concentrations. In six healthy male volunteers (all smokers), serum concentrations of theophylline (administered as aminophylline 400 mg single oral dose) were significantly higher following consumption of caffeine (2 to 7 cups of instant coffee over 24 hours, equivalent to approximately 120 to 630 mg of caffeine) than after caffeine deprivation for 48 hours. Caffeine consumption also increased the apparent elimination half-life of theophylline by an average of 32% and reduced its total body clearance by 23%. In another study, steady-state concentration and area under the concentration-time curve of theophylline (1200 mg intravenously over 24 hours) increased by 23% and 40%, respectively, in eight healthy volunteers following administration of caffeine (300 mg orally three times a day).

MANAGEMENT: Given the narrow therapeutic index of theophylline, patients should limit or avoid significant fluctuations in their intake of pharmacologic as well as dietary caffeine.

References

  1. Jonkman JH, Sollie FA, Sauter R, Steinijans VW (1991) "The influence of caffeine on the steady-state pharmacokinetics of theophylline." Clin Pharmacol Ther, 49, p. 248-55
  2. Sato J, Nakata H, Owada E, Kikuta T, Umetsu M, Ito K (1993) "Influence of usual intake of dietary caffeine on single-dose kinetics of theophylline in healthy human subjects." Eur J Clin Pharmacol, 44, p. 295-8

Switch to consumer interaction data

Moderate

ePHEDrine food

Applies to: Quadrinal (ephedrine / phenobarbital / potassium iodide / theophylline)

MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.

MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.

References

  1. Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
  2. Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
  3. (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
  4. (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
  5. (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
  6. (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
  7. (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
View all 7 references

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