Fastin Side Effects
Generic Name: phentermine
Note: This page contains information about the side effects of phentermine. Some of the dosage forms included on this document may not apply to the brand name Fastin.
For the Consumer
Applies to phentermine: oral capsule, oral capsule extended release, oral tablet, oral tablet disintegrating
In addition to its needed effects, some unwanted effects may be caused by phentermine (the active ingredient contained in Fastin). In the event that any of these side effects do occur, they may require medical attention.
Major Side Effects
You should check with your doctor immediately if any of these side effects occur when taking phentermine:Rare
- Seeing, hearing, or feeling things that are not there
- severe mental changes
- Chest pain
- decreased ability to exercise
- fast, irregular, pounding, or racing heartbeat or pulse
- numbness or tingling in the arms or legs
- swelling of the feet or lower legs
- trembling or shaking of the legs, arms, hands, or feet
- trouble breathing
- trouble with thinking, speaking, or walking
Minor Side Effects
Some of the side effects that can occur with phentermine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:Incidence not known:
- Decreased interest in sexual intercourse
- difficulty having a bowel movement (stool)
- dry mouth
- false or unusual sense of well-being
- hives or welts, itching, or skin rash
- inability to have or keep an erection
- increased in sexual ability, desire, drive, or performance
- increased interest in sexual intercourse
- loss in sexual ability, desire, drive, or performance
- redness of the skin
- unpleasant taste
For Healthcare Professionals
Applies to phentermine: compounding powder, oral capsule, oral capsule extended release, oral tablet, oral tablet disintegrating
Frequency not reported: Regurgitant cardiac valvular disease, primary pulmonary hypertension, palpitations, tachycardia, elevated blood pressure, precordial pain, ischemic events, angina, myocardial infarction, cardiac failure, cardiac arrest[Ref]
Frequency not reported: Rash[Ref]
Frequency not reported: Dry mouth, unpleasant taste, diarrhea, constipation, other gastrointestinal disturbances, nausea, vomiting, abdominal cramps[Ref]
Frequency not reported: Micturition disturbances[Ref]
Frequency not reported: Urticaria[Ref]
Frequency not reported: Overstimulation, restlessness, nervousness, dizziness, euphoria, dysphoria, tremor, headache, fatigue, cerebrovascular events[Ref]
Frequency not reported: Facial edema[Ref]
Frequency not reported: Insomnia, psychosis, impotence, libido changes, depression, hallucinations[Ref]
1. "Product Information. Lomaira (phentermine)." KVK-Tech Inc, Newtown, PA.
2. "Product Information. Adipex-P (phentermine)." Teva Pharmaceuticals (formerly Gate Pharmaceuticals), Sellersville, PA.
3. "Product Information. Phentermine Hydrochloride (phentermine)." Teva Pharmaceuticals USA, North Wales, PA.
4. Cerner Multum, Inc. "Australian Product Information." O 0
Not all side effects for Fastin may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.
More about Fastin (phentermine)
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Images
- Drug Interactions
- Support Group
- 55 Reviews – Add your own review/rating
- Drug class: anorexiants
Related treatment guides
Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.