Drug Interactions between Allergy Time and isoniazid
This report displays the potential drug interactions for the following 2 drugs:
- Allergy Time (chlorpheniramine)
- isoniazid
Interactions between your drugs
isoniazid chlorpheniramine
Applies to: isoniazid and Allergy Time (chlorpheniramine)
Consumer information for this interaction is not currently available.
GENERALLY AVOID: Coadministration of monoamine oxidase inhibitors (MAOIs) and antihistamines may result in additive central nervous system depressant effects. In addition, limited data suggest that MAOIs may potentiate and prolong the anticholinergic effects of antihistamines due to inhibition of catecholamine degradation, which may lead to overstimulation of the sympathetic nervous system. In one published report, a woman who had been on phenelzine 30 mg/day for six months developed irritability and visual hallucinations two months following the addition of cyproheptadine 2 mg at bedtime to treat phenelzine-induced anorgasmia. The hallucinations cleared over 48 hours following the discontinuation of her medications. In another published report, a patient developed delirium with symptoms of aggression, paranoia, and vivid auditory as well as visual hallucinations after two days of receiving diphenhydramine 300 mg/day and linezolid 600 mg every 12 hours. The patient also had tachycardia, very warm skin, and possibly blurred vision (as evidenced by constant squinting). Central anticholinergic intoxication and dopaminergic hyperactivity were suspected. Symptoms subsided over four days following the discontinuation of diphenhydramine, while linezolid was continued with no subsequent sequelae. In a third report, a patient developed visual hallucinations associated with confusion and disorientation after nine days of linezolid and antihistamine therapy, including dexchlorpheniramine and cetirizine for the first four days and hydroxyzine for the next five. Physical examination did not reveal any focal neurological signs, myoclonus or ataxia, and cerebral CT scan and EEG were within normal limits. Symptoms resolved two days after linezolid was discontinued.
MANAGEMENT: Prescribing antihistamines in combination with MAOIs or other agents that possess MAOI activity (e.g., furazolidone, linezolid, procarbazine) should generally be avoided. If concomitant treatment is unavoidable, patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities. It may be appropriate to monitor some patients for increased anticholinergic effects (e.g., constipation, urinary retention, fever, heat intolerance, blurred vision, confusion, hallucinations, dizziness, palpitations, arrhythmias, syncope), since certain populations such as the elderly and those with underlying organic brain disease tend to be more sensitive to these effects and may be susceptible to anticholinergic intoxication. It should be noted that the manufacturers of many of the sedating antihistamines (e.g., chlorpheniramine, dexchlorpheniramine, diphenhydramine, pheniramine, promethazine) consider their use within 14 days of MAOIs to be contraindicated.
References
- Kahn DA "Possible toxic interaction between cyproheptadine and phenelzine." Am J Psychiatry 144 (1987): 1242-3
- "Product Information. Periactin (cyproheptadine)." Merck & Co., Inc PROD (2002):
- "Product Information. Benadryl (diphenhydramine)." Parke-Davis PROD (2002):
- "Product Information. Matulane (procarbazine)." Roche Laboratories PROD (2001):
- Serio RN "Acute delirium associated with combined diphenhydramine and linezolid use." Ann Pharmacother 38 (2004): 62-5
- Ferry T, Ponceau B, Simon M, et al. "Possibly linezolid-induced peripheral and central neurotoxicity: report of four cases." Infection 33 (2005): 151-4
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Canadian Pharmacists Association "e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink" (2006):
- Cerner Multum, Inc. "Australian Product Information." O 0
Drug and food interactions
isoniazid food
Applies to: isoniazid
Food decreases the levels of isoniazid in your body. Take isoniazid on an empty stomach at least 1 hour before or 2 hours after a meal. This will make it easier for your body to absorb the medication. If nausea occurs, ask your doctor if you can take isoniazid with food. Avoid alcohol while taking isoniazid. Alcohol may increase the risk of damage to the liver during isoniazid treatment. Alcohol can also cause isoniazid side effects to get worse. Contact your doctor if you experience flushing, chills, headache, nausea, vomiting, and diarrhea.
chlorpheniramine food
Applies to: Allergy Time (chlorpheniramine)
Alcohol can increase the nervous system side effects of chlorpheniramine such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with chlorpheniramine. Do not use more than the recommended dose of chlorpheniramine, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.
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
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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