Pholcodine Health Dictionary

A natural re?ex reaction to irritation of the AIR PASSAGES and LUNGS. Air is drawn into the air passages with the GLOTTIS wide open. The inhaled air is blown out against the closed glottis, which, as the pressure builds up, suddenly opens, expelling the air – at an estimated speed of 960 kilometres (600 miles) an hour. This explosive exhalation expels harmful substances from the respiratory tract. Causes of coughing include infection – for example, BRONCHITIS or PNEUMONIA; in?ammation of the respiratory tract associated with ASTHMA; and exposure to irritant agents such as chemical fumes or smoke (see also CROUP).

The explosive nature of coughing results in a spray of droplets into the surrounding air and, if these are infective, hastens the spread of colds (see COLD, COMMON) and INFLUENZA. Coughing is, however, a useful reaction, helping the body to rid itself of excess phlegm (mucus) and other irritants. The physical e?ort of persistent coughing, however, can itself increase irritation of the air passages and cause distress to the patient. Severe and protracted coughing may, rarely, fracture a rib or cause PNEUMOTHORAX. Coughs can be classi?ed as productive – when phlegm is present – and dry, when little or no mucus is produced.

Most coughs are the result of common-cold infections but a persistent cough with yellow or green sputum is indicative of infection, usually bronchitis, and sufferers should seek medical advice as medication and postural drainage (see PHYSIOTHERAPY) may be needed. PLEURISY, pneumonia and lung CANCER are all likely to cause persistent coughing, sometimes associated with chest pain, so it is clearly important for people with a persistent cough, usually accompanied by malaise or PYREXIA, to seek medical advice.

Treatment Treatment of coughs requires treatment of the underlying cause. In the case of colds, symptomatic treatment with simple remedies such as inhalation of steam is usually as e?ective as any medicines, though ANALGESICS or ANTIPYRETICS may be helpful if pain or a raised temperature are among the symptoms. Many over-the-counter preparations are available and can help people cope with the symptoms. Preparations may contain an analgesic, antipyretic, decongestant or antihistamine in varying combinations. Cough medicines are generally regarded by doctors as ine?ective unless used in doses so large they are likely to cause sedation as they act on the part of the brain that controls the cough re?ex.

Cough suppressants may contain CODEINE, DEXTROMETHORPHAN, PHOLCODINE and sedating ANTIHISTAMINE DRUGS. Expectorant preparations usually contain subemetic doses of substances such as ammonium chloride, IPECACUANHA, and SQUILL (none of which have proven worth), while demulcent preparations contain soothing, harmless agents such as syrup or glycerol.

A list of systemic cough and decongestant preparations on sale to the public, together with their key ingredients, appears in the British National Formulary.... cough

See also MEDICINES. Government legislation covers the manufacture, sale and prescription of drugs in the UK. As well as stating which drugs may be sold over the counter (OTC) without a doctor’s or dentist’s prescription, and those which can be obtained only with such a prescription, government regulations determine the extent of availability of many substances which are liable to be abused – see Misuse of Drugs Act 1971 (below). The Misuse of Drugs Regulations 1985 de?ne those individuals who in their professional capacity are authorised to supply and possess controlled drugs: see the schedules of drugs listed below under the 1985 regulations.

Misuse of Drugs Act 1971 This legislation forbids activities relating to the manufacture, sale and possession of particular (controlled) drugs. These are classi?ed into three grades according to their dangers if misused. Any o?ences concerning class A drugs, potentially the most damaging when abused, carry the toughest penalties, while classes B and C attract lesser penalties if abused.

Class A includes: cocaine, dextromoramide, diamorphine (heroin), lysergic acid (LSD), methadone, morphine, opium, pethidine, phencyclidine acid and injectable preparations of class B drugs.

Class B includes: oral amphetamines, barbiturates, codeine, glutethimide, marijuana (cannabis), pentazocine and pholcodine.

Class C includes: drugs related to the amphetamines, anabolic and androgenic steroids, many benzodiazepines, buprenorphine, diethyl propion, human chorionic gonadotrophin (HCG), mazindol, meprobamate, pemoline, phenbuterol, and somatropin.

Misuse of Drugs Regulations 1985 These regulations de?ne those people who are authorised in their professional capacity to supply and possess controlled drugs. They also describe the requirements for legally undertaking these activities, such as storage of the drugs and limits on their prescription.

Drugs are divided into ?ve schedules and some examples follow.

I: Almost all are prohibited except in accordance with Home O?ce authority: marijuana (cannabis), LSD.

II: High potential for abuse but have

accepted medical uses: amphetamines, cocaine.

III: Lower potential for abuse: barbiturates, meprobamate, temazepam.

IV: Lower potential for abuse than I to III. Minimal control: benzodiazepines.

V: Low potential for abuse: generally compound preparations containing small amounts of opioids: kaolin and morphine (antidiarrhoeal medicine), codeine linctus (cough suppressant).

(See also CONTROLLED DRUGS.)... misuse of drugs

(cough suppressant) n. a drug, such as *pholcodine (a weak opioid), that suppresses coughing, possibly by reducing the activity of the cough centre in the brain and by depressing respiration. Some opioid analgesics also have antitussive activity, e.g. *codeine, *diamorphine, and *methadone.... antitussive