Hedon® has analgesic, antipyretic and anti-inflammatory actions.
Prosatglandins are associated with the develpment of pain. Aspirin and paracetamol inhibit the synthesis of prostaglandins, thus producing analgesia.
In fever, prostaglandins (PGE2) act within the hypothalamus to produce the resultant elevation of body temperature by processes that appear to be mediated by cyclic AMP. Aspirin and paracetamol suppress this response by inhibiting the synthesis of PGE2. Aspirin also has anti-inflammatory action as it is a much stronger inhibitor of prostaglandin (which are involved in the pathogenesis of inflammation) synthesis than paracetamol.
Caffeine relaxes smooth muscles, stimulates the central nervous system and cardiac muscles. Due to these effects it causes a reduction in drowsiness and fatigue and also causes a more rapid and clear flow of thought.
Orally ingested aspirin is absorbed rapidly, partly from the stomach but mostly from the upper small intestines. Appreciable concentrations are found in plasma in less than 30 minutes; after a single dose, a peak value is reached in about 2 hours and then gradually declines. Rate of absorption is determined by many factors, particularly the disintegration and dissolution rates if tablets are given, the pH at the nucosal surfaces and gastric emptying time. After absorption, aspirin is distributed throughout most body tissues and most trans-cellular fluids, primarily by pH-dependent passive processes.
Aspirin is actively transported by a low-capacity saturable system out of the CSF across the choroids plexus.
The drug readily crosses the placenta barrier. The biotransformation of aspirin takes place in many tissues, but particularly in the hepatic endoplasmic reticulum and mitochondria. The three chief metabolic products are salicyluric acid (the glycine conjugate), the ether or phenolic glucuronide and the ester or acyl glucuronide.
Paracetamol is metabolized primarily by the hepatic microsomal enzymes. Paracetamol is rapidly and almost completely absorbed from the gastrointestinal tract. The concentration in plasma reaches a peak in 30 to 60 minutes and the half-life in plasma is about 2 hours after therapeutic doses. Paracetamol is relatively uniformly distributed throughout most body fluids.
Binding of the drug to plasma proteins is variable; only 20 to 50% may be bound at the concentrations encountered during acute intoxication.
After therapeutic doses, 90 to 1005 of the drug may be recovered in the urine within the first day, primarily after hepatic conjugation with glucuronic acid (about 60%), sulfuric acid (about 35%) or cysteine (about 3%); small amouts of hydroxylated and deacetylated metabolies have also been detected. Children have less capacity for glucuronidation of the drug than do adults.
Caffeine is readily absorbed after oral administration and maximum plasma concentrations are achieved within 1 hour. Caffeine is distributed into all body compartments. It is eliminated primarily by metabolism in the liver. Less than 5% of the amount administered is recovered in the urine unchanged. Caffeine has a half-life of 3 to 7 hours.
Hedon tablets are indicated for mild to moderate pain, headaches, inflammatory pyrexia, acute and chronic rheumatic disease and musculoskeletal disorders.
Dosage and administration
To be taken every 3-4 hours. Adult and children over 12 years; 1-2 tablets. Maximum daily dosage of 8 tablets.
Hypersensitivity to any of the ingredients. Hypoprothrombinaemia, haemophilia and active peptic ulceration.
Hedon should be used with caution in patients with a history of peptic ulceration, coagulation abnormalities, impaired renal or hepatic function or in dehydrated patients.
Hedon may enhance the effects of anti-coagulants, oral hypoglycaemic agents, phenytoin and sodium valproate. It may inhibit the uricosuric action of probenecid and increase the toxicity of sulphonamides
Hedon may precipitate bronchospasm or induce attacks of asthma in susceptible patients.
Hedon should be avoided in the last 3 months of pregnancy.
Hedon should not be given to children below 12 years.
Hedon may induce hypersensitivity, asthma, urate kidney stones, chronic gastro-intestinal blood loss, tinnitus, nausea and vomiting. Hedon may rarely cause allergic reactions such as skin rashes, hives or itching.