Interacting drugs - also known as (N-Acetyl -P-Aminophenol ) APAP, Paracetamol

Drug Intractions summary

Acetoamionophen + Barbiturates/carbamazepine/Hydantoin/Rifampicin/Sufinpyrazole

Potenial hepatotoxicity of APAP increased by large doses  or long term admin. due to hepatic microsomal enzymes induction . The therapeutic effects of APAP also decreased

Alcohol ethyl 

chronic excessive ingestion apparently increases the toxicity of larger therapeutic doses or overdoses of APAP

Charcoal activated

Administered immediately , reduces acetaminophen absorption

Musculo-skeletal pain, and painful disorders.

Isolated reports of agranulocytosis.thrombocytopenia.

Skin rash,minor G.I. upsets

Rarely haemolysis(G6PD deficiency)

Hypersentivity.

Special precautions:

Impaired hepatic/renal function.

Indications:

Anagesic-antipyretic in presence of aspirin allergy. Haemostatic disturbances, bleeding diathesis, hemphilia. GI disease,Gouty arthiritis, Arthritic and rheumatic conditions, Musculo-skeletal pain, and painful disorders.

Dosage:

Adults- 325- 650 mg every 4 to 6 hours or I g 3-4 times/day. Do not exceed 4 g/day.

Children- May repeat 4 to 5 times daily. Do not exceed 5 doses in 24 hours.

Below 1 year - 40 to 80 mg. 1 to 2 - 120 mg, 2 to 3 - 160 mg ,4 to 5- 240 mg, 6 to 8- 320 mg. 9 to 10- 400 mg, 11- 480 mg..

Acetoaminophen

1. Severe or recurrent pain or high or continued fever may indicate serious illness. If pain persists for more than 5 days, if redness is present in or in arthritic and rheumatic conditions affecting children less than 12 years, consult physican immediately.

2. Do not exceed the recommended dosage. Consult physician for use in children less than 3 years of age, or for oral use less than 5 days (children), 10days (adults) for fever.

3. Dose of acetaminophen will be different for different patients. Follow your doctors orders or directions on the label

4. For diabetic patients- acetoamniphen may interfere with the results of some blood glucose(sugar) tests. If you notice any change in your results, check with your doctor. This is especially important if your diabetes is not well controlled.

5. For patients taking products containing caffeine- Caffeine may interfere with the results or a test that uses adenosine or dypyridamole, to help to find out how well your blood is following. Therefore you should not have any caffeine for 8 to 12 hours before the test.

Other Instructions

1. Individual Allergy - Tell your doctor if you have ever had any unusual or allergic reaction to acetoaminophen or aspirin. Also tell your doctor if you are allergic to any other substances such as foods, preservatives or dyes.

2. Pregnancy - Aceoaminophen has not been reported to cause birth defects or other problems

3. Breast feeding - Not reported to cause problems in nursing babies

4. Children - Some childrens products containing acetamoniphen also contain aspartame, which may be dangerous if it is given to children with phenylketonia.

5. Other medicines - Certain medicines should not be used at all. Tell your doctor if you are taking any other non-prescription or OTC medicine. Do not take Aspirin or other salicylates together with acetaminophen for more than a few days, unless your doctor has directed you to do so.

 6. Other medical problems- Presence of some other medical problems may affect the use of acetaminophen- Tell your doctor if you are suffering from any other  medical problems Alcohol abuse, Kidney disease, Hepatitis or other liver diseases- side efects may be increased. Phenylketonuria- brands containing aspartame can make your condition worse.

7. Medical tests- Acetaminophen may interfere with the results of some medical tests. Inform your doctor, and ask whether may be taken 3 or 4 days before the tests to be carried out.

Acetaminophen may cause false results with some blood glucose (sugar ) tests, especially in patients where diabetes is not well controlled. Patients taking products that containing caffeine in addition to acetaminophen, caffeine may interfere with results of tests that uses adenosine to find out how well your blood is flowing through the certain blood vessels. Therefore you should not have caffeine for 8 to 12 hours before the test.

8.Storage-  Keep out of reach of children. Store away from heat and direct light. Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

9. Interaction with food Absorption of acetaoaminophen is rapid from the GI tract. May be taken with meals.

Pharmacology :

Acetaminophen is the principal active metabolite of acetin and acetanilid, but has less toxicity in the usual recommended dose. APAP reduces fever by a direct action on the hypothalamic heat-regulatin centres, which increases dissipation of body heat (via vasodilation and sweating). Aspirin is clearly superior to APAP for pain of inflammatory origin.

Pharmacokinetics :

Absorption of acetaminophen is rapid and almost complete from GI tract. Peak plasma levels occur within 0.5 to 2 hours. Acetaminophen is extensively metabolised and excreted in urine primarily as inactive glucuronate and sulfate conjugates.

Absorption of acetaoaminophen is rapid from the GI tract. May be taken with meals.

Pregnancy:

It is routinely used during all stages of pregnancy. When used in therapeutic doses it appears safe for short term use. Continuous high daily dosage caused severe anaemia in a mother.

Lactation:

Acetaminophen is excreted in breast milk in low concentrations. No adverse effects in nursing infants reported