Skip to main content

Drug Interactions between Ionamin and Pondimin

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

Edit list (add/remove drugs)

Interactions between your drugs

Major

phentermine fenfluramine

Applies to: Ionamin (phentermine) and Pondimin (fenfluramine)

CONTRAINDICATED: The efficacy of centrally-acting appetite suppressants in combination with other anorectic agents has not been studied, but available data suggest that combined use may have the potential for serious cardiac problems. In a case-control epidemiological study, the use of anorectic agents was associated with an increased risk of pulmonary hypertension, a rare but often fatal disorder, and use for longer than three months was associated with a 23-fold increase in risk. Increased risk of pulmonary hypertension with repeated courses of therapy cannot be excluded. The use of some anorectic agents such as fenfluramine and dexfenfluramine has been associated with valvular heart disease. Possible contributing factors include use for extended periods of time, higher than recommended dosages, and/or use in combination with other anorectic drugs.

MANAGEMENT: Centrally--acting appetite suppressants should not be used in combination with other anorectic agents, including prescription, over-the-counter, and herbal preparations. In addition, they are not recommended for patients who have used any anorectic agents within the prior year. The potential risk of possible serious adverse effects such as valvular heart disease and pulmonary hypertension should be assessed carefully against the benefit of weight loss, and baseline cardiac evaluation should be considered to detect preexisting valvular heart diseases or pulmonary hypertension prior to initiating treatment. These agents are not recommended for use in patients with known heart murmur or valvular heart disease, severe hypertension, or symptomatic cardiovascular disease including arrhythmias. Patients should be advised to immediately discontinue the medication and contact their physician if they experience potential signs and symptoms of pulmonary hypertension such as new onset or aggravation of exertional dyspnea, chest pain or tightness, syncope, and lower extremity edema.

References

  1. "Product Information. Meridia (sibutramine)." Knoll Pharmaceutical Company PROD (2001):
  2. "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn PROD (2001):
  3. "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals (2012):
  4. "Product Information. Diethylpropion Hydrochloride SR (diethylpropion)." Watson Pharmaceuticals (2012):
  5. "Product Information. Phendimetrazine Tartrate SR (phendimetrazine)." Sandoz Inc (2012):
View all 5 references

Switch to consumer interaction data

Drug and food interactions

Moderate

phentermine food

Applies to: Ionamin (phentermine)

GENERALLY AVOID: Alcohol may potentiate the central nervous system and cardiovascular effects of centrally-acting appetite suppressants. In one study, concurrent administration of methamphetamine (30 mg intravenously) and ethanol (1 gm/kg orally over 30 minutes) increased heart rate by 24 beats/minute compared to methamphetamine alone. This increases cardiac work and myocardial oxygen consumption, which may lead to more adverse cardiovascular effects than either agent alone. Subjective effects of ethanol were diminished in the eight study subjects, but those of methamphetamine were not affected. The pharmacokinetics of methamphetamine were also unaffected except for a decrease in the apparent volume of distribution at steady state.

MANAGEMENT: Concomitant use of centrally-acting appetite suppressants and alcohol should be avoided if possible, especially in patients with a history of cardiovascular disease. Patients should be counselled to avoid hazardous activities requiring complete 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.

References

  1. Mendelson J, Jones RT, Upton R, Jacob P 3rd "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther 57 (1995): 559-68
  2. "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn PROD (2001):
  3. "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals (2012):

Switch to consumer interaction data

Moderate

fenfluramine food

Applies to: Pondimin (fenfluramine)

GENERALLY AVOID: Alcohol may potentiate the central nervous system and cardiovascular effects of centrally-acting appetite suppressants. In one study, concurrent administration of methamphetamine (30 mg intravenously) and ethanol (1 gm/kg orally over 30 minutes) increased heart rate by 24 beats/minute compared to methamphetamine alone. This increases cardiac work and myocardial oxygen consumption, which may lead to more adverse cardiovascular effects than either agent alone. Subjective effects of ethanol were diminished in the eight study subjects, but those of methamphetamine were not affected. The pharmacokinetics of methamphetamine were also unaffected except for a decrease in the apparent volume of distribution at steady state.

MANAGEMENT: Concomitant use of centrally-acting appetite suppressants and alcohol should be avoided if possible, especially in patients with a history of cardiovascular disease. Patients should be counselled to avoid hazardous activities requiring complete 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.

References

  1. Mendelson J, Jones RT, Upton R, Jacob P 3rd "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther 57 (1995): 559-68
  2. "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn PROD (2001):
  3. "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals (2012):

Switch to consumer interaction data

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.

Duplication

Stimulants

Therapeutic duplication

The recommended maximum number of medicines in the 'stimulants' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'stimulants' category:

  • Ionamin (phentermine)
  • Pondimin (fenfluramine)

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.

Duplication

Anorexiants

Therapeutic duplication

The recommended maximum number of medicines in the 'anorexiants' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'anorexiants' category:

  • Ionamin (phentermine)
  • Pondimin (fenfluramine)

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.

See also

Report options

Loading...
QR code containing a link to this page

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.

Medical Disclaimer