Drug Interactions between aminophylline / ephedrine / guaifenesin / phenobarbital and cholestyramine
This report displays the potential drug interactions for the following 2 drugs:
- aminophylline/ephedrine/guaifenesin/phenobarbital
- cholestyramine
Interactions between your drugs
PHENobarbital aminophylline
Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital and aminophylline / ephedrine / guaifenesin / phenobarbital
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 (4)
- Upton RA (1991) "Pharmacokinetic interactions between theophylline and other medication (Part I)." Clin Pharmacokinet, 20, p. 66-80
- Bukowskyj M, Nakatsu K, Munt PW (1984) "Theophylline reassessed." Ann Intern Med, 101, p. 63-73
- Landay RA, Gonzalez MA, Taylor JC (1978) "Effect of phenobarbital on theophylline disposition." J Allergy Clin Immunol, 62, p. 27-9
- 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
cholestyramine PHENobarbital
Applies to: cholestyramine and aminophylline / ephedrine / guaifenesin / phenobarbital
Cholestyramine may decrease the absorption of phenobarbital. The clinical significance is unknown. Phenobarbital should be administered at least one hour before or four to six hours after cholestyramine. Patients should be monitored for altered phenobarbital effects.
References (1)
- (2002) "Product Information. Questran (cholestyramine)." Par Pharmaceutical Inc
ePHEDrine aminophylline
Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital and aminophylline / ephedrine / guaifenesin / phenobarbital
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 (5)
- Weinberger M, Bronsky E, Bensch GW, Bock GN, Yecies JJ (1975) "Interaction of ephedrine and theophylline." Clin Pharmacol Ther, 17, p. 585-92
- Sims JA, doPico GA, Reed CE (1978) "Bronchodilating effect of oral theophylline-ephedrine combination." J Allergy Clin Immunol, 62, p. 15-21
- Tinkelman DG, Avner SE (1977) "Ephedrine therapy in asthmatic children. Clinical tolerance and absence of side effects." JAMA, 237, p. 553-7
- Weinberger MM, Brousky EA (1974) "Evaluation of oral bronchodilator therapy in asthmatic children: bronchodilators in asthmatic children." J Pediatr, 84, p. 421-7
- 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
Drug and food interactions
PHENobarbital food
Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital
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 (5)
- 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
- 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
- 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
- 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
- Seixas FA (1979) "Drug/alcohol interactions: avert potential dangers." Geriatrics, 34, p. 89-102
cholestyramine food
Applies to: cholestyramine
ADJUST DOSING INTERVAL: Bile acid sequestrants and the phosphate binder, sevelamer, can decrease the absorption of fat-soluble vitamins A, D, E, and K. By binding bile acids, these agents may interfere with normal fat digestion and absorption, thereby preventing the absorption of fat-soluble vitamins. When 8 grams of cholestyramine was administered simultaneously with a normal meal containing 250,000 units of vitamin A acetate in four healthy young adult subjects, plasma vitamin A levels were significantly reduced during a 9-hour postprandial period compared to the values obtained with the control meal. Coadministration with 4 grams of cholestyramine had no significant effect. In a crossover study involving healthy subjects, coadministration of sevelamer with calcitriol resulted in a significant reduction in bioavailability for calcitriol (calcitriol with sevelamer vs calcitriol alone: AUC 137 pg*h/mL vs 318 pg*h/mL and Cmax 40.1 pg/mL vs 49.7 pg/mL, respectively). Chronic use of bile acid sequestrants has been rarely associated with an increased bleeding tendency due to hypoprothrombinemia resulting from vitamin K deficiency. Isolated cases of Vitamin A (including one case of night blindness) and D deficiencies have also been reported with chronic cholestyramine therapy.
MANAGEMENT: When bile acid sequestrants are given for prolonged periods, some manufacturers recommend that concomitant supplementation with water-miscible or parenteral forms of fat-soluble vitamins be considered. If oral vitamin supplements are used with cholestyramine or colestipol, advise patients to take them at least 1 hour before or 4 to 6 hours after the bile acid sequestrant to minimize the potential impact on their absorption. No recommendations are available for sevelamer, but it may be advisable to follow the same precautions.
References (11)
- Gross L, Brotman M (1970) "Hypoprothrombinemia and hemorrhage associated with cholestyramine therapy." Ann Intern Med, 72, p. 95-6
- Shojania AM, Grewar D (1986) "Hypoprothrombinemic hemorrhage due to cholestyramine therapy." Can Med Assoc J, 134, p. 609-10
- Longstreth GF, Newcomer AD (1975) "Drug-induced malabsorption." Mayo Clin Proc, 50, p. 284-93
- Acuna R, Gonzalez Ceron M (1977) "Hypoprothrombinemia and bleeding associated to treatment with cholestyramine (author's transl)." Rev Med Chil, 105, p. 27-8
- (2001) "Product Information. Rocaltrol (calcitriol)." Roche Laboratories
- (2001) "Product Information. Welchol (colesevelam)." Daiichi Sankyo, Inc.
- (2005) "Product Information. Fosamax Plus D (alendronate-cholecalciferol)." Merck & Co., Inc
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Cerner Multum, Inc. "Australian Product Information."
- Peirce D, Hossack S, Poole L, et al. (2011) "The effect of sevelamer carbonate and lanthanum carbonate on the pharmacokinetics of oral calcitriol." Nephrol Dial Transplant, 26, p. 1615-21
- Vroonhof K, van Rijn HJM, van Hattum J (2003) "Vitamin K deficiency and bleeding after long-term use of cholestyramine." Neth J Med, 61, p. 19-21
ePHEDrine food
Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital
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 (7)
- 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
- 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
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
aminophylline food
Applies to: aminophylline / ephedrine / guaifenesin / phenobarbital
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 (7)
- 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
- 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
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
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
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
Further information
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