Phendimetrazine Side Effects
Phendimetrazine side effects are related to its stimulatory action on a variety of organ systems. The most common side effects of this drug are restlessness, anxiety, sweating, dizziness, agitation, sleeplessness, tremor, blurring of vision and psychosis.
The effects on the heart include palpitations, increased heart rate and high blood pressure. Other effects are nausea, altered bowel habits, dryness of mouth, frequent urination and changes in libido.
Phendimetrazine borrows its side effects from amphetamines, a group to which it is chemically related. Phendimetrazine also has the same abuse potential as the amphetamines. A past history of drug abuse or a profile susceptible to dependence is therefore a relative contraindication to this drug.
Phendimetrazine produces psychological dependence and can cause severe social dysfunction. Long-term therapy with Phendimetrazine produces severe skin changes, sleeplessness, irritability, hyperactivity and personality changes. At the extreme end of this spectrum, Phendimetrazine has been known to produce a psychotic condition not different from schizophrenia.
Phendimetrazine can aggravate hypertension and caution should be exercised when the patient on Phendimetrazine has even mild hypertension. Guanethidine, an antihypertensive drug may become ineffective when given along with Phendimetrazine. Phendimetrazine may impair certain judgment skills and so the patient should be cautioned about working with heavy machinery and driving.
Indiscriminate use can lead to overdosage of the drug. Acute overdose manifests itself as restlessness, confusion, hallucinations, aggressiveness and panic states. Fatigue and depression usually follow. Abnormal heartbeat rhythms and even heart failure can result due to overdosage. Toxicity due to the drug results in convulsions, coma and eventually death.
There are no specific antidotes for poisoning with Phendimetrazine and hence timely symptomatic, supportive therapy is required. Sedatives such as barbiturates are required to calm the patient. Hypertension is common and prompt antihypertensive therapy may be required.
In view of this skewed benefit/risk ratio, it is recommended that dosage be limited to the smallest possible effective amount of drug to minimize the possibility of overdose.