Available dosage forms of Phentermine

Phentermine – is a widely used drug for weight loss. To date, available dosage forms of Phentermine are conventional tablets and capsules, as well as extended-release capsules (ER) and orally disintegrating tablets (ODT).

Choice of Phentermine dosage form depends on several factors:

Content of an optimal dose of active ingredient necessary to provide a therapeutic effect
Dose selection for a particular patient taking into account its individual characteristics
The most convenient mode of application of the drug for the patient

Since Phentermine is a potent stimulant of the nervous system, its prolonged dosage forms make it possible to regulate rate of absorption of active ingredient. Thus, duration of Phentermine action increases.

Conventional tablets or capsules more often contain 37.5 mg of Phentermine Hydrochloride (equivalent: 30 mg of Phentermine base). An example of a drug that contains Phentermine Hydrochloride is tablets or capsules Adipex.

Conventional dosage forms of Phentermine Hydrochloride (capsules and tablets) are rapidly absorbed and reach the maximum concentrations in the blood plasma. However, rapid absorption of active component increases risk of side effects.

Another available dosage form of Phentermine is ODT. In the USA, these pills were sold under the brand Suprenza, but their current marketing status in the USA – Discontinued.

Advantages of using Suprenza ODT:

  • is irreplaceable if the patient has difficulty swallowing, since it dissolves in the mouth;
  • Suprenza ODT is absorbed much faster comparing to conventional tablets;
  • due to rapid absorption, Suprenza ODT contains a smaller amount of active ingredient (15 or 30 mg of Phentermine Hydrochloride).

Besides differences in dosage strengths of active ingredient and pharmacokinetic properties, all available dosage forms of Phentermine have certain similarities.

None of Phentermine dosage forms should not be prescribed to children younger than 12 years of age and to patients older than 65 years. The capsules, tablets and ODT should be used one or two times per day for a short period within 1 to 3 months.