Persantine (Dipyridamole) ® (dipyridamole USP) is a platelet inhibitor chemically described as 2,2',2",2"'-[(4,8- Dipiperidinopyrimido[5,4-]pyrimidine-2,6-diyl)dinitrilo]-tetraethanol. It has the following structural formula:
Dipyridamole is an odorless yellow crystalline powder, having a bitter taste. It is soluble in dilute acids, methanol and chloroform, and practically insoluble in water.
Persantine (Dipyridamole) tablets for oral administration contain:
It is believed that platelet reactivity and interaction with prosthetic cardiac valve surfaces, resulting in abnormally shortened platelet survival time, is a significant factor in thromboembolic complications occurring in connection with prosthetic heart valve replacement.
Persantine (Dipyridamole) tablets have been found to lengthen abnormally shortened platelet survival time in a dose-dependent manner.
In three randomized controlled clinical trials involving 854 patients who had undergone surgical placement of a prosthetic heart valve, Persantine (Dipyridamole) tablets, in combination with warfarin, decreased the incidence of postoperative thromboembolic events by 62 to 91% compared to warfarin treatment alone. The incidence of thromboembolic events in patients receiving the combination of Persantine (Dipyridamole) tablets and warfarin ranged from 1.2 to 1.8%. In three additional studies involving 392 patients taking Persantine (Dipyridamole) tablets and coumarin-like anticoagulants, the incidence of thromboembolic events ranged from 2.3 to 6.9%.
In these trials, the coumarin anticoagulant was begun between 24 hours and 4 days postoperatively, and the Persantine (Dipyridamole) ® (dipyridamole USP) tablets were begun between 24 hours and 10 days postoperatively. The length of follow-up in these trials varied from 1 to 2 years.
Persantine (Dipyridamole) tablets do not influence prothrombin time or activity measurements when administered with warfarin.
No pharmacokinetic drug-drug interaction studies were conducted with Persantine (Dipyridamole) (dipyridamole USP) tablets. The following information was obtained from the literature.
Adverse reactions at therapeutic doses are usually minimal and transient. On long-term use of Persantine (Dipyridamole) tablets initial side effects usually disappear. The following reactions in Table 1 were reported in two heart valve replacement trials comparing Persantine (Dipyridamole) tablets and warfarin therapy to either warfarin alone or warfarin and placebo:
Other reactions from uncontrolled studies include diarrhea, vomiting, flushing and pruritus. In addition, angina pectoris has been reported rarely and there have been rare reports of liver dysfunction. On those uncommon occasions when adverse reactions have been persistent or intolerable, they have ceased on withdrawal of the medication.
When Persantine (Dipyridamole) ® (dipyridamole USP) tablets were administered concomitantly with warfarin, bleeding was no greater in frequency or severity than that observed when warfarin was administered alone. In rare cases, increased bleeding during or after surgery has been observed.
In post-marketing reporting experience, there have been rare reports of hypersensitivity reactions (such as rash, urticaria, severe bronchospasm, and angioedema), larynx edema, fatigue, malaise, myalgia, arthritis, nausea, dyspepsia, paresthesia, hepatitis, thrombocytopenia, alopecia, cholelithiasis, hypotension, palpitation, and tachycardia.
In case of real or suspected overdose, seek medical attention or contact a Poison Control Center immediately. Careful medical management is essential. Based upon the known hemodynamic effects of dipyridamole, symptoms such as warm feeling, flushes, sweating, restlessness, feeling of weakness and dizziness may occur. A drop in blood pressure and tachycardia might also be observed.
Symptomatic treatment is recommended, possibly including a vasopressor drug. Gastric lavage should be considered. Administration of xanthine derivatives (e.g., aminophylline) may reverse the hemodynamic effects of dipyridamole overdose. Since dipyridamole is highly protein bound, dialysis is not likely to be of benefit.
Persantine (Dipyridamole) tablets are available as round, orange, sugar-coated tablets of 25 mg, 50 mg and 75 mg coded BI/17, BI/18 and BI/19, respectively.
They are available in bottles of 100 tablets as indicated below: 25 mg Tablets (NDC 0597-0017-01) 50 mg Tablets (NDC 0597-0018-01) 75 mg Tablets (NDC 0597-0019-01)
