Interactions
OHPC is not likely to affect most cytochrome P450 enzymes at therapeutic concentrations. Drug interaction studies have not been performed with OHPC. Pharmacology
Pharmacodynamics
OHPC has progestogenic activity, some antimineralocorticoid activity, and no other important hormonal activity. Progestogenic activity
OHPC, also known as 17α-hydroxyprogesterone caproate, is closer to progesterone in terms of structure and pharmacology than most other progestins, and is essentially a pure progestogen – that is, a selective agonist of the progesterone receptor (PR) with minimal or no other hormonal activity. However, OHPC has improved pharmacokinetics compared to progesterone, namely a much longer duration with intramuscular injection in oil solution.Administered by intramuscular injection, the endometrial transformation dosage of OHPC per cycle is 250 to 500 mg, and the weekly substitution dosage of OHPC is 250 mg, while the effective dosage of OHPC in the menstrual delay test (Greenblatt) is 25 mg per week. An effective ovulation-inhibiting dosage of OHPC is 500 mg once per month by intramuscular injection. However, the dose of OHPC used in once-a-month combined injectable contraceptives is 250 mg, and this combination is effective for inhibition of ovulation similarly. For comparison, the dose of medroxyprogesterone acetate (MPA; 6α-methyl-17α-hydroxyprogesterone acetate), a close analogue of OHPC, used by intramuscular injection in microcrystalline aqueous suspension in once-a-month combined injectable contraceptives, is 25 mg. It has also been said that given by intramuscular injection, 250 mg OHPC in oil solution is equivalent in progestogenic potency to 50 mg medroxyprogesterone acetate in microcrystalline aqueous suspension.
Non-steroidal anti-inflammatory drugs (NSAIDs) have also been used. Hydroxychloroquine has proven effective in some cases. History
In a 1985 paper published in the Journal of the American Medical Association, McCarty and colleagues first described a case series of patients with this disorder, for which they coined the abbreviation RS3PE. RS3PE was initially thought to represent a form of seronegative rheumatoid arthritis but is now believed to be a separate syndrome. == References ==