How to Calculate a Benztropine Equivalent

Benztropine is a anticholinergic drug that is prescribed to treat Parkinson's disease and other disorders of the muscular nervous system. Benztropine works to reduce the muscle contraction disorder, tremor and hypersalivation associated with Parkinson's disease by inhibiting the actions of muscarinic receptors located in smooth muscle tissue. There are several related substances that provide anticholinergic effects that are similar to those caused by benztropine; benztropine equivalency refers to the relative amount of an anticholinergic substance that must be administered in order to match the anticholinergic effects of benztropine.

Things You'll Need

• Calculator

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Instructions

• 1

  Check with a doctor before consuming benztropine or any related substance. Benztropine can cause mild side effects such as dry mouth and constipation. It can also cause more serious side effects including delirium, memory loss and death.

• 2

  Determine the type of anticholinergic substance for which you wish to calculate the benztropine equivalency. Substances for which benztropine equivalency ratios have been calculated include trihexyphenedyl, biperiden, diphenhydramine, amantadine, haloperidol and clozapine.

• 3

  Multiply the amount of benztropine, as measured in milligrams, by your anticholinergic substance's benztropine equivalency ratio. Trihexyphenedel and biperiden both have benztropine equivalency ratios of 1-to-1. Diphenhydramine and haloperidol both have equivalency ratios of 10 to 15 milligrams per 1 milligram of benztropine. Amantadine has a benztropine equivalency ratio of 25 milligrams per 1 milligram of benztropine, while clozapine has an equivalency ratio of 50 to 100 milligrams per 1 milligram of benztropine.

  The result of the above calculation is the amount of the anticholinergic substance that you must use to create an effect equivalent to the dose of benztropine in question. This is the substance's benztropine equivalent.