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Drug Interactions between Bactrim and ephedrine / phenobarbital / potassium iodide / theophylline

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

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Interactions between your drugs

Major

trimethoprim potassium iodide

Applies to: Bactrim (sulfamethoxazole / trimethoprim) and ephedrine / phenobarbital / potassium iodide / theophylline

Using trimethoprim together with potassium iodide may increase potassium levels in the blood. High levels of potassium can develop into a condition known as hyperkalemia, which in severe cases can lead to kidney failure, muscle paralysis, irregular heart rhythm, and cardiac arrest. You may be more likely to develop hyperkalemia while using these medications if you are elderly; dehydrated; have kidney disease, diabetes, or advanced heart failure; or if you are receiving trimethoprim for long periods of time or in high dosages to treat serious infections such as Pneumocystis jiroveci pneumonia (PCP) in AIDS. Regular or long-term use of nonsteroidal anti-inflammatory drugs such as ibuprofen or naproxen (Aleve) may also increase your risk. It is important that you maintain adequate fluid intake during treatment with these medications. In addition, talk to your doctor to see if you should limit consumption of potassium-rich foods such as tomatoes, raisins, figs, potatoes, lima beans, bananas, plantains, papayas, pears, cantaloupes, mangoes, and potassium-containing salt substitutes. You should seek medical attention if you experience nausea, vomiting, weakness, confusion, tingling of the hands and feet, feelings of heaviness in the legs, a weak pulse, or a slow or irregular heartbeat, as these may be symptoms of hyperkalemia. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Moderate

trimethoprim PHENobarbital

Applies to: Bactrim (sulfamethoxazole / trimethoprim) and ephedrine / phenobarbital / potassium iodide / theophylline

PHENobarbital may reduce the blood levels of trimethoprim, which may make the medication less effective in treating some conditions. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Moderate

theophylline PHENobarbital

Applies to: ephedrine / phenobarbital / potassium iodide / theophylline and ephedrine / phenobarbital / potassium iodide / theophylline

Using PHENobarbital together with theophylline may decrease the effects of theophylline. Contact your doctor if your condition changes or if you experience breathing difficulties. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Minor

theophylline ePHEDrine

Applies to: ephedrine / phenobarbital / potassium iodide / theophylline and ephedrine / phenobarbital / potassium iodide / theophylline

Information for this minor interaction is available on the professional version.

Drug and food interactions

Major

PHENobarbital food

Applies to: ephedrine / phenobarbital / potassium iodide / theophylline

Ask your doctor before using PHENobarbital together with ethanol, this can add to dizziness, drowsiness and other side effects of PHENobarbital. Be careful if you drive or do activities that require you to be awake and alert. Talk with your doctor before using any medications together, or drinking alcohol with PHENobarbital. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Moderate

theophylline food

Applies to: ephedrine / phenobarbital / potassium iodide / theophylline

Both smoking and excessive caffeine consumption can alter the blood levels of theophylline, which may affect the dosing. Tobacco and marijuana smoke (including secondhand exposure) generally reduces, while caffeine increases, blood levels. In addition, caffeine is a stimulant and may add to the side effects of theophylline such as headache, insomnia, and increases in blood pressure and heart rate. It is best to avoid smoking and to limit caffeine consumption during theophylline therapy. Talk to a healthcare professional if you have any questions or concerns. If you start smoking or undergo smoking cessation, your doctor may need to monitor your blood levels more closely to determine if you need a dose adjustment of theophylline. You should stop taking theophylline and seek medical attention if you experience potential signs and symptoms of excessive drug levels such as nausea, vomiting, persistent headache, insomnia, and rapid heartbeat. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

When theophylline is given with enteral (tube) feedings, blood levels may be decreased due to interference with its absorption. This may reduce the effectiveness of the medication. To minimize potential for interaction, you may interrupt the feeding for one hour before and one hour after the theophylline dose. You may need more frequent blood tests to monitor theophylline levels.

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Moderate

sulfamethoxazole food

Applies to: Bactrim (sulfamethoxazole / trimethoprim)

Ask your doctor before using sulfamethoxazole together with ethanol. Contact your doctor if you experience unpleasant side effects such as fast heartbeats, warmth or redness under your skin, tingly feeling, nausea, or vomiting. If you experience these side effects, you may need to avoid ethanol while taking sulfamethoxazole. You should check your food and medicine labels to see if these products contain ethanol. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Moderate

theophylline food

Applies to: ephedrine / phenobarbital / potassium iodide / theophylline

Ask your doctor before using theophylline together with caffeine. Using these medications together may increase some of the side effects of theophylline. This can cause nausea, vomiting, insomnia, tremors, restlessness, uneven heartbeats, and seizure (convulsions). Avoid drinks or foods that contain caffeine, such as coffee, tea, cola, and chocolate. You may need a dose adjustment or special test if you use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

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Moderate

ePHEDrine food

Applies to: ephedrine / phenobarbital / potassium iodide / theophylline

Consumer information for this interaction is not currently available.

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

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.


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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.