Clozapine

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Clozapine is a new type of atypical antipsychotics drug used in the treatment of schizophrenia (including psychosis in Parkinson’s disease) in patients unresponsive to, or intolerant of, conventional antipsychotic drugs. It is used principally in patients who have not responded to other drugs, or who have experienced intolerable side-effects with other drugs. Schizophrenia is an illness which interferes with a person’s ability to think clearly, manage emotions, make decisions and distinguish between reality and fantasy.

The drug helps control severe resistant schizophrenia, helping to re-establish a more normal lifestyle. Improvement is gradual and relief of severe symptoms can take more than three weeks. Treatment is always started and supervised by a hospital. Clozapine is less likely to cause the parkinsonism effects (tremor and stiffness) that may occur with the use of other antipsyschotic drugs. However, the medication can cause a serious side effect called agranulocytosis (a large decrease in white blood cells) Blood test would be done before and during treatment. Clozapine would only be prescribed if the tests appeared normal. All patients would be registered with the Clozaril Patient Monitoring Services (CPMS).

Quick Guide

• Atypical antipsychotic danger of overdose – MEDIUM.
• Dependency is said to be – LOW.
• Prescription only drug – YES.
• Available as generic – NO (generic drugs, short: generics) is a drug which is produced and distributed without patent protection.
• Alcohol Avoidance – YES.
• Alcohol may increase the sedative effect of clozapine.
• Always take Clozaril tablets exactly as your doctor has told you.
• Always read the manufacturer’s information leaflet before beginning treatment.
• Try to take clozapine at the same times each day to avoid missing any doses.

Side Effects

You may if prescribed clozapine suffer one or more of these side effects in the initial stages. However, you may find you do not suffer any at all. It does not follow that being on this medication will always cause unwanted adverse effects. Some individuals have reported no side-effects.

Common: Constipation, Drowsiness, dizziness, Excess Saliva (drooling), Dizziness, Dry Mouth, Fainting, Tiredness, Weight Gain
Rare: Fever, Fits, Blurred Vision, Sore Throat, Tremor, Fast Heartbeat, Muscle Rigidity, hyperglycaemia.

The side effects listed here are the most common and rare problems reported by patients using clozapine It may not include all of the side effects reported by the drug’s manufacturer. If common side effects persist you need to inform your doctor. Notify your doctor if you suffer any of the rare or some other side effects not listed here. For total peace of mind, seek information from your doctor or chemist.

Prolonged Use

*Agranulocytosis (acute infection characterized by severe sore throat, fever, and fatigue and associated with an extreme reduction of white blood cells) may occur and occasionally liver function may be upset. Significant weight gain may also occur, blood may need to be monitored weekly for a period of time, then fortnightly until the end of the first year.

About three fourth of all agranulocytosis in the United States is related to drugs. Procainamide, anti-thyroid drugs and sulfasalazine are at the top of the list of drugs causing this problem. Most agranulocytosis is related to the direct effect related to its dose. Phenothiazines, semi-synthetic penicillins, non-steroidal anti-inflammatory drugs (NSAIDs), aminopyrine derivatives, benzodiazepines, barbiturate, gold compounds, sulfonamides, and anti-thyroid medications are the most common causes of neutropenia and agranulocytosis.

*Note:
Agranulocytos… This complaint is beyond the medical knowledge of this website. I have provided a link to Medicine World for those who wish to understand this problem and how other drugs can cause this complaint. Which can result in death.

Driving, Hazardous Work & Alcohol

Avoid driving/hazardous work until you know how clozapine affects you. Clozapine can cause drowsiness, blurred vision, and dizziness. Avoid alcohol as it may increase the sedative effect of clozapine. Manufacturers advise not to drink alcohol at all.

Pregnancy and Breast-Feeding

Discuss with your doctor as it is not known if problems could occur in pregnancy (not usually prescribed). The drug passes into the breast milk and could have an effect on your baby. Discuss both issues with your doctor.

Patient information shows Clozapine as Category B… Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, only if the potential benefits of the drug in pregnant women out-weigh the potential risks to the fetus.

Surgery Or dental Procedure

It would be advisable if you discussed any form of medication you may be taking with your doctor/dentist or if you need to undergo surgery or dental work.

Tell Your Doctor Or Pharmacist

You should tell your doctor if you have a current health problem. For example: heart disease, kidney problems, if you are pregnant or you intend to become pregnant, or if you think you may be at risk from drug treatment for any other reason. Some types of medication can cause serious adverse effects when taken side by side so it is important to tell your doctor of any other medication you are already taking. This should also include any over-the-counter medication. For example: Painkillers, cold remedies, (herbal and complimentary / alternative medication.

Over 60′s & Children

The initial dose for elderly patients would be low, gradually increasing as adverse effects may result when prescribed for this age group. Side Effects may consist of faintness or light-headedness after changing position, dizziness, fast heart beat, difficulty in passing urine, and constipation. This drug would not be prescribed for infants or children.

In elderly people with dementia, a small increase in the number of people dying has been reported for patients taking antipsychotics compared with those not taking antipsychotics.

Overdose

An unintentional extra dose is unlikely to cause problems. However, large overdoses may cause Drowsiness, tiredness, lack of energy, unconsciousness, coma, confusion, hallucinations, agitation, incoherent speech, stiff limbs, trembling hands, seizures (fits), increased production of saliva, widening of the black part of the eye, blurred vision, low blood pressure, collapse, fast or irregular heart beat, shallow or difficult breathing. Notify your Doctor.

Failing this go to your nearest accident and emergency department of your local hospital. Take the container with you. This will help the hospital staff identify what has been taken and work towards given the right kind of help without delay.

Other Medication Reactions

All drugs that have a sedative effect on the nervous system will more likely than not increase the the sedative properties of this drug. A number of drugs increase the risk of adverse effects on the blood. fluoxetine, fluvoxamine, paroxetine and sertraline increase plasma concentration of clozapine. There is also a possible increased risk of antimuscarinic side-effects when tricyclics are given with this drug. Do not take other medication with out checking with your doctor or pharmacist first.

Avoid concomitant (two or more drugs used or given at or almost the same time) use of clozapine with azapropazone (NSAIDs) as there could be an increased risk of agranulocytosis (lowered white blood cell count).

Missed A Dose

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and continue the regular dosing schedule. Do not take a double dose to make up for a missed one.

Reducing or Stopping Medication

It is important that you do not change your dose or stop taking Clozaril without asking your doctor first. Continue taking the tablets for as long as your doctor tells you. Stoping suddenly may result in withdrawal effects. These reactions include sweating, headache, nausea (feeling sick), vomiting (being sick) and diarrhoea. It may also lead to a worsening of the condition.

Effect Of Medication (from one dose)

Effects could be felt within 3 to 5 days however, it may be 3 weeks or more before the full benefit is felt.

Safety and Storage

• Never take more than the original dosage prescribed by your doctor.
• If your due to have treatment like an operation or dental work tell the person carrying out the treatment which medicines you are taking.
• When you buy any medicines over-the-counter check with the pharmacist that they are safe to take with your other medicines.
• Never take Clozapine if it has past the expiry date shown on the box or container.
• Do not store medication above a temperature of 25°C or above a working area where high condensation may exit.
• Keep Clozapine in its original container, in a cool dry place, away from the reach and eye sight of children.
• Always read the printed information leaflet that comes with your medicine if possible, before beginning treatment.
• Do not discard old or unwanted drugs into your trash, sink or toilet.
• Return all unused or old medicines/drugs to your pharmacist. who will dispose of them safely. without causing unwanted effects on our environment.

If this medication has been prescribed for you never allow anyone else to use it, even if you know or others feel their symptom are similar to your own.

Do not leave your doctors surgery until you have a clear understanding of what the drug your doctor has prescribed for you does, and why you have been prescribed it. It is common for people who do not understand the reason behind there treatment to take their medication correctly.

Reference:

• Novartis Pharmaceuticals UK Ltd. Patient Information Leaflet (PIL) last updated on electronic Medicines Compendium eMC: 07-Jun-10. Clozaril Tablets 25mg and 100mg.
• British National Formulary – 61st Edition (March 2011) British Medical Association and Royal Pharmaceutical Society of Great Britain, London.