Cilostazol

About Cilostazol

Cilostazol and several of its metabolites block the enzyme phosphodiesterase III, raising cyclic AMP in platelets and blood vessels, which makes platelets less likely to clump and widens blood vessels. The label approves it to reduce the symptoms of intermittent claudication, as shown by an increase in walking distance; safety and effectiveness in children have not been established. The dose is 100 mg twice a day, taken at least half an hour before or two hours after breakfast and dinner, and it is lowered to 50 mg twice a day with strong or moderate CYP3A4 inhibitors or with CYP2C19 inhibitors. Some people improve within 2 to 4 weeks, but up to 12 weeks may be needed, and the label says to stop it if symptoms have not improved after 3 months.

The boxed warning: cilostazol is contraindicated in heart failure of any severity, because several drugs that block phosphodiesterase III, as it does, shortened survival compared with placebo in people with class III to IV heart failure. It must not be taken by anyone allergic to it, and it is avoided with bleeding disorders or active bleeding. It can cause a fast heartbeat, palpitations, fast abnormal rhythms and low blood pressure, and a new heart murmur or heart symptoms after starting it need checking for obstruction of blood flow out of the heart. Low platelet and white cell counts, some progressing to agranulocytosis, have been reported, so blood counts are checked periodically. Headache, diarrhea, abnormal stools and palpitations are the most common side effects; dizziness, nausea and heartburn also occur.

The label’s examples of inhibitors that call for the lower dose are ketoconazole and itraconazole (strong CYP3A4), erythromycin and diltiazem (moderate CYP3A4), and ticlopidine, fluconazole and omeprazole (CYP2C19); it also lists grapefruit juice as a moderate CYP3A4 inhibitor. With aspirin in studies, bleeding side effects did not appear to increase, and clopidogrel does not significantly raise cilostazol levels. No dose change is needed for kidney impairment, although severe impairment raises metabolite levels; moderate or severe liver impairment has not been studied. The label asks nursing mothers to choose between breastfeeding and the drug. Pletal, approved in 1999, is listed as discontinued in both strengths.

Taking Cilostazol

How to take it

Twice a day, at least 30 minutes before or 2 hours after breakfast and dinner, at about the same times each day. You may notice improvement in 2 to 4 weeks, but the full benefit can take up to 12 weeks; it controls the symptoms but does not cure the condition. Do not stop it without talking to the prescriber.

If you miss a dose

Take it as soon as you remember, unless it is almost time for the next dose; then skip the missed dose. Do not take a double dose.

Storage

At room temperature, away from excess heat and moisture (not in the bathroom), out of reach of children. Use a take-back program rather than flushing.

Interactions to know about

The label lowers the dose to 50 mg twice a day with inhibitors such as ketoconazole, itraconazole, erythromycin, diltiazem, fluconazole and omeprazole, and lists grapefruit juice as a moderate inhibitor, so tell the prescriber about each and ask before drinking grapefruit juice. Also mention aspirin, clopidogrel and any other medicine that affects bleeding.

This summarizes the official prescribing information. Your prescriber’s and pharmacist’s instructions, and the leaflet that comes with your medicine, take priority.

Why the cash price for Cilostazol differs from pharmacy to pharmacy

With Pletal discontinued, every fill is a generic, so quotes differ mainly in each pharmacy’s dispensing fee and markup and in whether cilostazol is on its flat-price generic list. A pharmacy that rarely fills it may need to order it in.

Twice-daily dosing means a month’s supply is a large count of tablets where a pharmacy prices per tablet. When a CYP3A4 or CYP2C19 inhibitor calls for the 50 mg dose, the new strength is a separate prescription and fill.

Ways to pay less for Cilostazol without insurance

• Ask whether cilostazol is on the pharmacy’s flat-price generic list, and compare more than one pharmacy.
• Because the benefit can take up to 12 weeks to show, ask for a ninety-day supply once it is clearly helping.
• If your dose is 100 mg, check that it is written as one 100 mg tablet rather than two 50 mg tablets.
• If your symptoms have not improved after 3 months, ask the prescriber whether to stop it rather than keep refilling it.
• Upload the prescription to Script Unlock so licensed pharmacies can quote their cash price. You pay the pharmacy directly.

Questions to ask your pharmacist about Cilostazol

1. 1.Does any heart condition I have rule out cilostazol?
2. 2.How should I time my doses around breakfast and dinner?
3. 3.Do any of my medicines, such as omeprazole, diltiazem or an antibiotic or antifungal, mean I need the lower dose?
4. 4.Do I need blood counts while I take it, and what bleeding signs should I watch for?

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