Drug interactions between Adapin and isoproterenol/phenylephrine
| Results for the following 2 drugs: |
|---|
| Adapin (doxepin) |
| isoproterenol/phenylephrine |
Interactions between your selected drugs
doxepin ↔ phenylephrine
Applies to:Adapin (doxepin) and isoproterenol/phenylephrine
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.
doxepin ↔ isoproterenol
Applies to:Adapin (doxepin) and isoproterenol/phenylephrine
MONITOR: The concomitant use of isoproterenol and tricyclic antidepressants may increase the risk of arrhythmias, especially at high doses. The mechanism is not clear. Tachycardia has been reported in clinical studies. Rare cases of malignant cardiac arrhythmias have also been reported in patients who took oral isoproterenol and tricyclic antidepressants; however causality was not clearly established due to excessive doses ingested and the presence of other drugs.
MANAGEMENT: Patients receiving this combination should be monitored and advised to notify their physician if they experience a fast or irregular pulse.
See also...
Drug Interaction Classification
The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
| 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. |
Do not stop taking any medications without consulting your healthcare provider.
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