Thursday 12 June 2014

CHLOROQUINE - chloroquine phosphate tablet | Chloroquine phosphate 250mg tablets - malaria | CHLOROQUINE PHOSPHATE TABLETS, USP 250 MG

CHLOROQUINE - chloroquine phosphate tablet 
CHLOROQUINE - chloroquine phosphate tablet, coated 
TAJ PHARMA

CHLOROQUINE PHOSPHATE

TABLETS, USP 250 MG and 500 MG


or Malaria and Extraintestinal Amebiasis

DESCRIPTION

Chloroquine Phosphate, USP, is a 4-aminoquinoline compound for oral administration. It is a white, odorless, bitter tasting, crystalline substance, freely soluble in water.
Chloroquine Phosphate Tablets are an antimalarial and amebicidal drug.
Each tablet, for oral administration, contains 250 mg chloroquine phosphate (equivalent to 150 mg base) or 500 mg chloroquine phosphate (equivalent to 300 mg base).
Inactive ingredients 250 mg: Calcium Stearate, Colloidal Silicon Dioxide, Dibasic Calcium Phosphate, Microcrystalline Cellulose, and Talc.
Inactive ingredients 500 mg: Colloidal Silicon Dioxide, Corn Starch, Lactose Monohydrate, Magnesium Stearate, Microcrystalline Cellulose, Povidone, and Sodium Starch Glycolate. Film Coating and Polishing Solution contains: D&C Red #27 Aluminum Lake, D&C Yellow #10 Lake, FD&C Blue #1 Lake, Hydroxypropyl Methylcellulose, Polyethylene Glycol, and Polysorbate 80.
Chemically, it is 7-chloro-4-[[4-(diethylamino)-1-methylbutyl]amino] quinoline phosphate (1:2) and has the following structural formula:
Chloroquine phosphate (Klaw-roh-kwin foss-fate) is a medicine which is used in amoebic hepatitis and amoebic abscess, discoid lupus erythematosus, malaria, rheumatoid arthritis and systemic lupus erythematosus.
The information in this Medicine Guide for Chloroquine varies according to the condition being treated and the particular preparation used.
Chloroquine phosphate 250mg tablets
Information specific to Chloroquine phosphate 250mg tablets when used in malaria
    How to use your medicine – includes taking, storing and stopping your medicine, what to do if you take too much, plus the ingredients of your medicine.
    Warnings – covers the suitability of the medicine for you and side effects and interactions with other medicines.
    Your medicine and everyday activities – includes alcohol, your diet, complementary medicines and vitamins as well as driving.
    Family planning – provides advice about whether this medicine is suitable for you in pregnancy and breast feeding.
Chloroquine phosphate is used to prevent malaria as well as to treat acute attacks of malaria. It can do both because it attacks malaria parasites and prevents them multiplying.
Chloroquine phosphate, in the treatment of auto-immune diseases helps to suppress over activity in the immune system and limits inflammation. This helps to reduce signs and symptoms of the disease such as pain and swelling.
Chloroquine phosphate needs to be taken for a few months for autoimmune diseases before any improvement is noticed.
Other information about Chloroquine phosphate:
    to get the best results from Chloroquine phosphate take it after you have eaten a meal
Do not share your medicine with other people. It may not be suitable for them and may harm them.
The pharmacy label on your medicine tells you how much medicine you should take. It also tells you how often you should take your medicine. This is the dose that you and your prescriber have agreed you should take. You should not change the dose of your medicine unless you are told to do so by your prescriber.
If you feel that the medicine is making you unwell or you do not think it is working, then talk to your prescriber.
Some medicines work best if they are taken at a specific time of day. Getting the most benefit from your medicine can also be affected by what you eat, when you eat and the times at which you take other medicines.
Specific information on when to take Chloroquine phosphate can be found in the Patient Information Leaflet that comes with this medicine or on the medicine label. You can also ask your doctor or pharmacist for information about when to take your medicine.
Some medicines have specific instructions about how to take them. This is because they work better when taken correctly. These instructions can include getting the right dose and special instructions for preparing the medicine.
Specific information on how to take Chloroquine phosphate can be found in the Patient Information Leaflet that comes with this medicine or on the medicine label. Alternatively, you can request information about how to take your medicine from your doctor or pharmacist.
If you are having problems taking this form of Chloroquine phosphate, you should talk to your prescriber or pharmacist. They may be able to give you advice on other ways to take your medicine or other preparations that are easier for you to take.
Taking extra doses of some medicines can be harmful. In some cases even one extra dose can cause you problems. If you take extra doses of your medicine, you must get medical advice immediately. You may need a test to assess the effect of taking extra doses. This is because the effects of taking too much medicine are very complex so it is very important that you seek medical advice.
Contact your prescriber, pharmacist, specialist clinic or call 111 for advice.
Make sure you take all of your medicine containers with you if you are advised to go to hospital.
Suddenly stopping your medicine may cause your original condition to return. This is why you must speak to your prescriber if you are having any problems taking your medicine.
If you are not having any problems taking this medicine then do not stop taking it, even if you feel better, unless advised to do so by your prescriber.
If you are in any doubt, contact your prescriber, pharmacist, specialist clinic or call 111.
The instructions on how you should keep your medicine are on the pharmacy label. It is a good idea to keep your medicine in the original container. This will help to keep your medicine in the best condition and also allow you to check the instructions. Do not take the medicine if the packaging appears to have been tampered with or if the medicine shows any signs of damage. Make sure that the medicine is out of the sight and reach of children.
Specific information on how to look after Chloroquine phosphate can be found in the Patient Information Leaflet that comes with this medicine or on the medicine label. Alternatively, you can request information about how to look after your medicine from your doctor or pharmacist.
You must not take the medicine after the expiry date shown on the packaging. If you have any unused medicine, return it to your pharmacist who will dispose of it safely.
Chloroquine phosphate is not suitable for everyone and some people should never use it. Other people should only use it with special care. It is important that the person prescribing this medicine knows your full medical history.
Your prescriber may only prescribe this medicine with special care or may not prescribe it at all if you:
           are allergic or sensitive to or have had a reaction to any of the ingredients in the medicine
           are elderly
           drink alcohol heavily
           have kidney problems
           have liver problems
           have low blood sugar levels
           have or have had epilepsy
           have porphyria
           have psoriasisAs part of the process of assessing suitability to take this medicine a prescriber may also arrange tests:
  • to determine whether or not the medicine is suitable and whether it must be prescribed with extra care
  • to check that this medicine is not having any undesired effects
Over time it is possible that Chloroquine phosphate can become unsuitable for some people, or they may become unsuitable for it. If at any time it appears that Chloroquine phosphate has become unsuitable, it is important that the prescriber is contacted immediately.
A medicine is only made available to the public if the clinical trials have shown that the benefits of taking the medicine outweigh the risks.
Once a medicine has been licensed, information on the medicine's effects, both intended and unintended, is continuously recorded and updated.
Some side-effects may be serious while others may only be a mild inconvenience.
Everyone's reaction to a medicine is different. It is difficult to predict which side-effects you will have from taking a particular medicine, or whether you will have any side-effects at all. The important thing is to tell your prescriber or pharmacist if you are having problems with your medicine.

The frequency of these side-effects is unknown

  • abnormal laboratory test results
  • allergic and anaphylactic reactions including urticaria, angioedema and vasculitis
  • blindness
  • blood and bone marrow problems
  • blurred vision
  • changes in personality
  • convulsions
  • corneal opacities
  • deafness
  • decreased blood sugar levels - very low blood sugar levels may lead to loss of consciousness. Seek immediate medical advice if your blood sugar levels are low or you are having warning signs of low blood sugar levels
  • diarrhoea
  • double vision
  • ear or hearing problems
  • ECG changes
  • erythema multiforme
  • eye colour changes
  • eye or eyesight problems
  • feeling anxious
  • gastrointestinal problems
  • hair colour changes
  • hair loss
  • hallucinations
  • headaches
  • heart problems - these may occur if Chloroquine phosphate is given in high dose for a long period of time
  • itching
  • liver problems
  • lowered blood pressure
  • lung problems
  • muscle problems
  • nausea
  • neuromyopathy
  • photosensitivity
  • precipitation of psoriasis
  • problems with colour vision
  • psychosis or psychotic-like behaviour
  • skin and mucous membrane colour changes - these may occur if Chloroquine phosphate is given for a long period of time
  • skin problems
  • skin rash or rashes
  • Stevens-Johnson syndrome
  • stomach cramps
  • tinnitus
  • toxic epidermal necrolysis
  • visual field defects
  • vomiting
If you feel unwell or if you have concerns about a side-effect, you will need to seek advice. If you feel very ill, get medical help straight away. Contact your prescriber, pharmacist, nurse or call 111.

CLINICAL PHARMACOLOGY

Chloroquine is rapidly and almost completely absorbed from the gastrointestinal tract, and only a small proportion of the administered dose is found in the stools. Approximately 55% of the drug in the plasma is bound to nondiffusible plasma constituents. Excretion of chloroquine is quite slow, but is increased by acidification of the urine. Chloroquine is deposited in the tissues in considerable amounts. In animals, from 200 to 700 times the plasma concentration may be found in the liver, spleen, kidney, and lung; leukocytes also concentrate the drug. The brain and spinal cord, in contrast, contain only 10 to 30 times the amount present in plasma.
Chloroquine undergoes appreciable degradation in the body. The main metabolite is desethylchloroquine, which accounts for one fourth of the total material appearing in the urine; bisdesethylchloroquine, a carboxylic acid derivative, and other metabolic products as yet uncharacterized are found in small amounts. Slightly more than half of the urinary drug products can be accounted for as unchanged chloroquine.

Microbiology

Mechanism of Action

Chloroquine is an antimalarial agent. While the drug can inhibit certain enzymes, its effect is believed to result, at least in part from its interaction with DNA. However, the mechanism of plasmodicidal action of chloroquine is not completely certain.

Activity in vitro and in vivo:

Chloroquine is active against the erthyrocytic forms of Plasmodium vivax, Plasmodium malariae, and susceptible strains of Plasmodium falciparum (but not the gametocytes of P. falciparum). It is not effective against exoerythrocytic forms of the parasite.
In vitro studies with trophozoites of Entamoeba histolytica have demonstrated that chloroquine also possesses amebicidal activity comparable to that of emetine.

Drug Resistance:

Resistance of Plasmodium falciparum to chloroquine is widespread and cases of Plasmodium vivax have been reported.

INDICATIONS AND USAGE

Chloroquine Phosphate Tablets are indicated for suppressive treatment and for acute attacks of malaria due to P. vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum. The drug is also indicated for the treatment of extraintestinal amebiasis.
Chloroquine Phosphate Tablets do not prevent relapses in patients with vivax or malariae malaria because it is not effective against exoerythrocytic forms of the parasite, nor will it prevent vivax or malariae infection when administered as a prophylactic. It is highly effective as a suppressive agent in patients with vivax or malariae malaria, in terminating acute attacks, and significantly lengthening the interval between treatment and relapse. In patients with falciparum malaria it abolishes the acute attack and effects complete cure of the infection, unless due to a resistant strain of P. falciparum.

CONTRAINDICATIONS

Use of this drug is contraindicated in the presence of retinal or visual field changes either attributable to 4-aminoquinoline compounds or to any other etiology, and in patients with known hypersensitivity to 4-aminoquinoline compounds. However, in the treatment of acute attacks of malaria caused by susceptible strains of plasmodia, the physician may elect to use this drug after carefully weighing the possible benefits and risks to the patient.

WARNINGS

It has been found that certain strains of P. falciparum have become resistant to 4-aminoquinoline compounds (including chloroquine and hydroxychloroquine). Chloroquine resistance is widespread and, at present, is particularly prominent in various parts of the world including sub-Saharan Africa, Southeast Asia, the Indian subcontinent, and over large portions of South America, including the Amazon basin1.
Before using chloroquine for prophylaxis, it should be ascertained whether chloroquine is appropriate for use in the region to be visited by the traveler. Chloroquine should not be used for treatment of P. falciparum infections acquired in areas of chloroquine resistance or malaria occurring in patients where Chloroquine prophylaxis has failed.
Patients infected with a resistant strain of plasmodia as shown by the fact that normally adequate doses have failed to prevent or cure clinical malaria or parasitemia should be treated with another form of antimalarial therapy.
Irreversible retinal damage has been observed in some patients who had received long-term or high-dosage 4-aminoquinoline therapy. Retinopathy has been reported to be dose related.
When prolonged therapy with any antimalarial compound is contemplated, initial (base line) and periodic ophthalmologic examinations (including visual acuity, expert slit-lamp, funduscopic, and visual field tests) should be performed.
If there is any indication (past or present) of abnormality in the visual acuity, visual field, or retinal macular areas (such as pigmentary changes, loss of foveal reflex), or any visual symptoms (such as light flashes and streaks) which are not fully explainable by difficulties of accommodation or corneal opacities, the drug should be discontinued immediately and the patient closely observed for possible progression. Retinal changes (and visual disturbances) may progress even after cessation of therapy.
All patients on long-term therapy with this preparation should be questioned and examined periodically, including testing knee and ankle reflexes, to detect any evidence of muscular weakness. If weakness occurs, discontinue the drug.
A number of fatalities have been reported following the accidental ingestion of chloroquine, sometimes in relatively small doses (0.75 g or 1 g chloroquine phosphate in one 3-year-old child). Patients should be strongly warned to keep this drug out of the reach of children because they are especially sensitive to the 4-aminoquinoline compounds.
Use of Chloroquine Phosphate Tablets in patients with psoriasis may precipitate a severe attack of psoriasis. When used in patients with porphyria the condition may be exacerbated. The drug should not be used in these conditions unless in the judgment of the physician the benefit to the patient outweighs the potential risks.

Usage in Pregnancy:

Radioactively tagged chloroquine administered intravenously to pregnant pigmented CBA mice passed rapidly across the placenta and accumulated selectively in the melanin structures of the fetal eyes. It was retained in the ocular tissues for five months after the drug had been eliminated from the rest of the body2. There are no adequate and well-controlled studies evaluating the safety and efficacy of chloroquine in pregnant women. Usage of chloroquine during pregnancy should be avoided except in the suppression or treatment of malaria when in the judgement of the physician the benefit outweighs the potential risk to the fetus.

Chloroquine phosphate comes as a tablet to take by mouth. For prevention of malaria in adults, one dose is usually taken once a week on exactly the same day ...
 

No comments:

Post a Comment