What is cilostazol, and how does it work (mechanism of action)?
Cilostazol is a medication for the treatment of intermittent claudication, a condition caused by narrowing of the arteries
that supply the legs with blood. Patients with intermittent claudication develop
pain when they walk because not enough oxygen-containing blood reaches the
active leg muscles. Cilostazol reduces the pain of intermittent claudication by
dilating the arteries, thereby improving the flow of blood and oxygen to the
legs. (It does this by decreasing the action of an enzyme, phosphodiesterase
III.) It also reduces the ability of blood to clot. Cilostazol enables patients
with intermittent claudication to walk longer and faster before developing pain.
Cilostazol has a different mechanism of action than pentoxifylline (Trental),
the other drug approved for intermittent claudication. (Pentoxifylline improves
blood flow by making it easier for red blood cells to pass through vessels. It
also decreases the viscosity of blood.). The FDA approved cilostazol in January
What brand names are available for cilostazol?
Is cilostazol available as a generic drug?
Do I need a prescription for cilostazol?
What are the side effects of cilostazol?
The most common adverse effects of cilostazol are:
- abdominal pain,
- abnormal stool,
- upper respiratory tract infections,
- runny nose,
- fluid retention,
- dizziness and
- abnormal heartbeats.
Other important side effects which have also been reported with cilostazol include a reduction in numbers of white blood cells and platelets. Severe skin
reactions also have been reported.
Cilostazol inhibits the enzyme
phosphodiesterase III. Other drugs that inhibit this enzyme have caused death in
individuals with heart failure. Therefore, individuals with heart failure should
not use cilostazol.
What is the dosage for cilostazol?
The dose is 100 mg twice daily. Cilostazol should be taken at
least half an hour before or two hours after dinner and breakfast to prevent
food from affecting its absorption.
Salt and sodium are the same.
Which drugs or supplements interact with cilostazol?
Erythromycin (E.E.S, Erythrocin), omeprazole (Prilosec)
and diltiazem (Cardizem) increase the concentration of cilostazol by blocking
the action of enzymes that destroy cilostazol. Though not specifically studied,
a similar interaction could occur with ketoconazole (Nizoral), itraconazole (Sporanox),
fluconazole (Diflucan), miconazole (Monistat), fluvoxamine (Luvox), fluoxetine
(Prozac), nefazodone (Serzone) and sertraline (Zoloft). Diltiazem (Cardizem) and omeprazole (Prilosec) also increase concentrations of cilostazol.
Higher concentrations of cilostazol could increase the
possibility of toxic effects. Therefore, a dose of 50 mg twice daily should be
considered when drugs that may increase the concentration of cilostazol also are
Combining pletal with other drugs that interfere with the blood
clotting process may increase the likelihood of bleeding.
A high fat meal
increases the absorption of cilostazol. Grapefruit juice could increase the
concentration of cilostazol. Therefore, grapefruit juice should not be taken by
patients on cilostazol.
Is cilostazol safe to take if I’m pregnant or breastfeeding?
The use of cilostazol in
pregnancy has not been adequately
Cilostazol has not been adequately studied in women
who are breastfeeding.
What else should I know about cilostazol?
What preparations of cilostazol are available?
Tablets: 50 and 100 mg
How should I keep cilostazol stored?
Tablets should be stored below 25 C (77 F). Brief exposures
to 30 C (86 F) are allowed.