Anagrelide belongs to the family of medications called platelet-reducing agents. This medication is used to manage a condition called thrombocythemia, where your body produces too many platelets. Platelets are cells in your blood that help clots to form when you bleed.

If your body makes too many platelets, it is hard for your blood to flow normally and it will be more likely to clot or bleed. This can cause medical problems such as heart attacks, stroke, blood clots in the lung or legs, as well as bleeding from the stomach, gums, or nose. Anagrelide works by slowing down platelet production.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual recommended adult starting dose of anagrelide is 0.5 mg 4 times daily or 1 mg 2 times daily for at least 7 days. After a week, your doctor will have you gradually increase the dose until an effective dose is reached. Laboratory tests performed at regular intervals will be used to monitor the number of platelets in your blood. It is very important to keep these lab appointments, as there is a narrow margin between too much and too little of the medication. Usually, your platelet count will begin to respond within 7 to 14 days when you have reached the proper dose of medication for you. Doses higher than 10 mg per day or 2.5 mg in a single dose are not recommended.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

This medication works only while you are taking it. If you stop taking anagrelide, the number of platelets in your blood quickly increases. Speak to your doctor before stopping this medication.

If you miss a dose when you are just starting this medication, call your doctor or pharmacist for advice. If you miss a dose during long-term treatment, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not take this medication if you:

• are allergic to anagrelide or any ingredients of the medication
• have severe liver disease

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• back pain
• chills
• constipation
• decreased appetite
• diarrhea
• difficulty sleeping
• dizziness when rising from a sitting or lying position
• eye irritation or infection
• fatigue
• flu-like symptoms (e.g., cough, headache, sore throat)
• flushing
• gas and bloating
• general feeling of being unwell
• headache
• muscle aches and pains
• nausea
• ringing in the ears
• skin irritation (redness and itchiness)
• spinning, whirling sensation
• stomach pain
• sweating
• tingling sensations or numbness
• weight changes
• vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• confusion
• decreased sense of touch
• dehydration
• fever
• increased blood pressure
• memory loss
• pounding or irregular heartbeat
• signs and symptoms of bleeding (e.g., easy bruising, nosebleeds, blood in urine or stools, bleeding gums, cuts that don't stop bleeding)
• signs and symptoms of breathing problems (e.g., shortness of breath, troubled breathing, wheezing, or tightness in chest, fast or irregular breathing)
• signs and symptoms of heart problems (e.g., fast, irregular heartbeat or pulse, chest pain, difficulty breathing, swelling in the ankles and legs)
• signs and symptoms of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• signs and symptoms of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs and symptoms of bronchitis or pneumonia (e.g., fever, cough, shortness of breath)
• symptoms of irregular heartbeat (e.g., chest pain, dizziness, rapid, pounding heartbeat, shortness of breath)
• trouble swallowing
• vision changes

Stop taking the medication and seek immediate medical attention if any of the following occur:

• chest pain
• fainting/loss of consciousness
• dizziness or fainting with irregular heart rhythm
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worse when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)
• trouble breathing or shortness of breath

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Heart disease: Anagrelide can cause an increased heart rate, a feeling of a racing or pounding heartbeat, swelling in the legs or ankles, and trouble breathing. If you have confirmed or suspected heart disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart rhythm: This medication can cause changes to the normal rhythm of the heart, including an irregular heartbeat called QT prolongation. QT prolongation is a life-threatening condition that can cause fainting, seizures, and sudden death. If you are at risk for heart rhythm problems (e.g., people with heart failure, angina, low potassium, or magnesium levels), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: Anagrelide may affect the function of the kidneys for those who already have kidney problems. Your doctor will monitor your kidney function while you are taking this medication. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: The liver is largely responsible for removing anagrelide from the body. Decreased liver function may result in a build-up of this medication in the body, leading to side effects. If you have a history of liver problems, your doctor should monitor your liver function closely while you are taking anagrelide. In some cases, your doctor may need to adjust the dose of medication that you take. Anagrelide should not be used by anyone who has severe liver problems.

Lung inflammation: Lung inflammation (interstitial lung disease), causing difficulty breathing, has occurred on rare occasions in some people taking this medication. This complication can be serious and sometimes fatal. If you experience new or worsening shortness of breath or cough (with or without fever) at any time while you are taking anagrelide, contact your doctor immediately.

Pregnancy: Women who may become pregnant while taking this medication should use reliable birth control while taking anagrelide. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if anagrelide passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children less than 16 years of age.

There may be an interaction between anagrelide and any of the following:

• acetylsalicylic acid
• alfuzosin
• amantadine
• amiodarone
• antihistamines (e.g,. cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• apixaban
• apomorphine"azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• buprenorphine
• buserelin
• chloral hydrate
• chloroquine
• clopidogrel
• dabigatran
• dipyridamole
• disopyramide
• domperidone
• dronedarone
• edoxaban
• efavirenz
• famotidine
• fingolimod
• flecainide
• formoterol
• galantamine
• glucosamine
• grapefruit juice
• heparin
• herbal products that affect blood clotting (e.g., cat's claw, chamomile, fenugreek, evening primrose, feverfew, garlic, ginger, ginseng, turmeric)
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• hydroxychloroquine
• indacaterol
• indapamide
• lithium
• loperamide
• low-molecular-weight heparins (e.g., dalteparin, enoxaparin, tinzaparin)
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• maprotiline
• mefloquine
• methadone
• metronidazole
• mifepristone
• mirabegron
• mirtazapine
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• multivitamin supplements
• non-steroidal anti-inflammatory medications (NSAIDs; e.g., diclofenac, ketorolac, naproxen)
• octreotide
• omega-3-fatty acids
• pentamidine
• pentoxifylline
• prasugrel
• primaquine
• procainamide
• propafenone
• protein kinase inhibitors (e.g., bosutinib, dasatinib, imatinib, nilotinib, sunitinib)quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, norfloxacin, ofloxacin)
• rilpivirine
• riociguat
• romidepsin
• rivaroxaban
• salmeterol
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• serotonin antagonists (anti-emetic medications; e.g., granisetron, ondansetron)
• serotonin-norepinephrine reuptake inhibitors (SNRIs; desvenlafaxine, duloxetine, venlafaxine)
• solifenacin
• sotalol
• sucralfate
• sulfamethoxazole
• sucralfate
• tacrolimus
• tamoxifen
• tetrabenazine
• theophylline
• ticagrelor
• ticlopidine
• tizanidine
• tolterodine
• trazodone
• trimethoprim
• tricyclic antidepressasnts (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• urokinase
• vardenafil
• vitamin E
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.