Drug Interactions between Adapin and Tedrigen
This report displays the potential drug interactions for the following 2 drugs:
- Adapin (doxepin)
- Tedrigen (ephedrine/phenobarbital/theophylline)
Interactions between your drugs
doxepin ePHEDrine
Applies to: Adapin (doxepin) and Tedrigen (ephedrine / phenobarbital / theophylline)
GENERALLY AVOID: Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents and vasoconstrictor-containing local anesthetics. Several-fold increases in the effects of norepinephrine and, to a lesser extent, epinephrine and phenylephrine were reported in healthy subjects pretreated with desipramine, imipramine, or nortriptyline. The mechanism is TCA inhibition of norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, hypertension, throbbing headache, tremor, palpitation, chest pain, and cardiac dysrhythmia have been reported in association with this interaction. Various TCAs have been implicated including amitriptyline, desipramine, imipramine, nortriptyline, and protriptyline. It is not known whether the interaction also occurs with mixed-acting sympathomimetic agents (e.g., dopamine, ephedrine, metaraminol).
MANAGEMENT: Parenteral administration of direct-acting sympathomimetic agents should preferably be avoided during therapy with tricyclic antidepressants except in cases of emergency (e.g., treatment of anaphylaxis). If concomitant use is necessary, initial dose and rate of administration of the sympathomimetic should be reduced, and cardiovascular status including blood pressure should be monitored closely. Although clinical data are lacking, it may be prudent to follow the same precaution with mixed-acting sympathomimetic agents.
References
- Mitchell JR, Cavanaugh JH, Arias L, Oates JA (1970) "Guanethidine and related agents. III: antagonism by drugs which inhibit the norepinephrine pump in man." J Clin Invest, 49, p. 1596-604
- Svedmyr N (1968) "The influence of a tricyclic antidepressive agent (protriptyline) on some of the circulatory effects of noradrenaline and adrenaline in man." Life Sci, 7, p. 77-84
- Boakes AJ, Laurence DR, Teoh PC, Barar FS, Benedikter LT, Pritchard BN (1973) "Interactions between sympathomimetic amines and antidepressant agents in man." Br Med J, 1, p. 311-5
- Borg KO, Johnsson G, Jordo L, Lundborg P, Ronn O, Welin-Fogelberg I (1979) "Interaction studies between three antidepressant drugs (zimelidine, imipramine and chlorimipramine) and noradrenaline in healthy volunteers and some pharmacokinetics of the drugs studied." Acta Pharmacol Toxicol (Copenh), 45, p. 198-205
- Linnoila M, Karoum F, Calil HM, Kopin IJ, Potter WZ (1982) "Alteration of norepinephrine metabolism with desipramine and zimelidine in depressed patients." Arch Gen Psychiatry, 39, p. 1025-8
- ed., Boakes AJ. Vasoconstrictors in local anaesthetics and tricyclic antidepressants. In: Grahame-Smith, DG (1977) "Drug Interactions. QV 38 D7932 1975." Baltimore, MD: University Park Press, p. 275-83
- Fritz H, Hagstam KE, Lindqvist B (1965) "Local skin necrosis after intravenous infusion of norepinephrine, and the concept of endotoxinaemia. A clinical study on 10 cases." Acta Med Scand, 178, p. 403-16
- Teba L, Schiebel F, Dedhia HV, Lazzell VA (1988) "Beneficial effect of norepinephrine in the treatment of circulatory shock caused by tricyclic antidepressant overdose." Am J Emerg Med, 6, p. 566-8
- Goulet JP, Perusse R, Turcotte JY (1992) "Contraindications to vasoconstrictors in dentistry: Part III. Pharmacologic interactions." Oral Surg Oral Med Oral Pathol, 74, p. 692-7
- Niemegeers CJ, Lenaerts FM, Artois KS, Janssen PA (1977) "Interaction of drugs with apomorphine, tryptamine and norepinephrine. A new 'in vivo' approach: the ATN-test in rats." Arch Int Pharmacodyn Ther, 227, p. 238-53
- Ghose K (1980) "Sympathomimetic amines and tricyclic antidepressant drugs." Neuropharmacology, 19, p. 1251-4
theophylline PHENobarbital
Applies to: Tedrigen (ephedrine / phenobarbital / theophylline) and Tedrigen (ephedrine / phenobarbital / 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
- 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
doxepin PHENobarbital
Applies to: Adapin (doxepin) and Tedrigen (ephedrine / phenobarbital / theophylline)
MONITOR: Tricyclic antidepressants may counteract the anticonvulsive effects of barbiturates by lowering the seizure threshold. Barbiturates may decrease the serum levels and effects of tricyclic antidepressants by induction of hepatic metabolism. In addition, the respiratory-depressant effects of both agents may be increased due to additive pharmacologic effects.
MANAGEMENT: If the barbiturate is being taken for a seizure disorder, patients should be closely monitored for loss of seizure control. Dose adjustments may be required. Monitoring for clinical evidence of additive toxicity and for clinical and/or laboratory evidence of reduced antidepressant effect is also advisable.
References
- Crocker J, Morton B (1969) "Tricyclic (antidepressant) drug toxicity." Clin Toxicol, 2, p. 397-402
- Burrows GD, Davies B (1971) "Antidepressants and barbiturates." Br Med J, 4, p. 113
- Silverman G, Braithwaite R (1972) "Interaction of benzodiazepines with tricyclic antidepressants." Br Med J, 4, p. 111
- Spina E, Avenoso A, Campo GM, Caputi AP, Perucca E (1996) "Phenobarbital induces the 2-hydroxylation of desipramine." Ther Drug Monit, 18, p. 60-4
- Garey KW, Amsden GW, Johns CA (1997) "Possible interaction between imipramine and butalbital." Pharmacotherapy, 17, p. 1041-2
theophylline ePHEDrine
Applies to: Tedrigen (ephedrine / phenobarbital / theophylline) and Tedrigen (ephedrine / phenobarbital / 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
- 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: Tedrigen (ephedrine / phenobarbital / 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
- 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
theophylline food
Applies to: Tedrigen (ephedrine / phenobarbital / 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
- 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
- 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
- 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
doxepin food
Applies to: Adapin (doxepin)
GENERALLY AVOID: Concomitant use of ethanol and a tricyclic antidepressant (TCA) may result altered TCA plasma levels and efficacy, and additive impairment of motor skills, especially driving skills. Acute ethanol ingestion may inhibit TCA metabolism, while chronic ingestion of large amounts of ethanol may induce hepatic TCA metabolism.
MANAGEMENT: Patients should be advised to avoid alcohol during TCA therapy. Alcoholics who have undergone detoxification should be monitored for decreased TCA efficacy. Dosage adjustments may be required.
References
- Dorian P, Sellers EM, Reed KL, et al. (1983) "Amitriptyline and ethanol: pharmacokinetic and pharmacodynamic interaction." Eur J Clin Pharmacol, 25, p. 325-31
- Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
- Sandoz M, Vandel S, Vandel B, Bonin B, Allers G, Volmat R (1983) "Biotransformation of amitriptyline in alcoholic depressive patients." Eur J Clin Pharmacol, 24, p. 615-21
- Ciraulo DA, Barnhill JG, Jaffe JH (1988) "Clinical pharmacokinetics of imipramine and desipramine in alcoholics and normal volunteers." Clin Pharmacol Ther, 43, p. 509-18
- Seppala T, Linnoila M, Elonen E, Mattila MJ, Makl M (1975) "Effect of tricyclic antidepressants and alcohol on psychomotor skills related to driving." Clin Pharmacol Ther, 17, p. 515-22
- Ciraulo DA, Barnhill JG, Jaffe JH, Ciraulo AM, Tarmey MF (1990) "Intravenous pharmacokinetics of 2-hydroxyimipramine in alcoholics and normal controls." J Stud Alcohol, 51, p. 366-72
- Ciraulo DA, Alderson LM, Chapron DJ, Jaffe JH, Subbarao B, Kramer PA (1982) "Imipramine disposition in alcoholics." J Clin Psychopharmacol, 2, p. 2-7
theophylline food
Applies to: Tedrigen (ephedrine / phenobarbital / 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
- 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
- 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
ePHEDrine food
Applies to: Tedrigen (ephedrine / phenobarbital / 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
- 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
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.
Tranquilizers
Therapeutic duplication
The recommended maximum number of medicines in the 'tranquilizers' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'tranquilizers' category:
- Adapin (doxepin)
- Tedrigen (ephedrine/phenobarbital/theophylline)
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
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
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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