Drugs - Uses And Addiction
Drug - WHAT is it?
In simple terms, substances that interact with a biochemical target to produce a biological response are called drugs. When the biological response is therapeutic and is used in diagnosis, prevention and treatment of diseases, these substances are called medicines. If used in higher doses than recommended, these very medicines turn into potential poisons.
Psychoactive or psychotropic drugs
These are the substances that alter mood, perception, behaviour, feelings, etc. for sometime temporarily.
Habituation / Drug dependence
Continued and uncontrolled intake of drugs leads to habituation or dependence which can be Physiological (physical) or Psychological.
PHYSIOLOGICAL DEPENDENCE - In this type of dependence, the concerned drug has infiltrated into a metabolic machinery of the body so that its sudden stop of intake will lead to severe withdrawal symptoms.
PSYCHOLOGICAL DEPENDENCE - It is the dependence of the body over that particular drug just in the form of thought so that its sudden stop of intake will not cause any withdrawal symptoms.
IMPORTANT CLASSES OF DRUGS
I) Sedatives and Tranquilizers
- Sedatives are recommended to the patients of insomnia(inability to sleep). E.g. Barbiturates. These are derivatives of barbituric acid viz.,veronal, seconal, amytal, nembutal.
- They are hypnotic i.e. sleep producing. They have a calming effect on the body as they slow down the speed of impulse conduction (by keeping the chloride channels of post synaptic membrane for longer periods of time). Their withdrawal includes symptoms like headache, dizziness, chills, skin rashes, etc.
- Tranquilizers are used for treatment of stress, depression and various neurotic and psychotic diseases. Accordingly we have minor(mild) and major(strong) classes of tranquilizers.
- The minor ones are antidepressants and are given to neurotic patients. They contain benzodiazepines. Some examples are alprax (alprozolam), librium, nitrazepam, lorazepam, diazepam, valium.
- Equanil, a tranquilizer, is used to control depression and hypertension. Chlordiazepoxide and meprobamate, relatively mild tranquilizers, are used to relieve tension.
- Major tranquilizers are given to psychotic people under violent attack and are used in the treatment of schizophrenia, delusional disorders and other other psychotic diseases. They contain phenothiazenes.
- Addiction of tranquilizers can even lead to infertility in the long run and can damage memory.
II) Opiate Narcotics
- They are severe depressants of the central nervous system, CNS.
- Opium(afeem) is obtained as a white latex from the unripe capsules of opium poppy plant.
Opium and its derivatives are called opiates.
- They are potent analgesics (pain relievers)
- Opiate receptors are present in our body on gastrointestinal tract and in brain.
- EFFECTS ON BODY - They reduce cardiac output, respiratory rate, promote ADH production, loss of appetite and weight loss, induce disinterest in work and lethargy, cause constriction of pupils and hence affects acuteness of vision, induce sterility and sometimes pose a risk of dangerous diseases like AIDS and hepatitis B.
Derivatives of Opium
- Codeine- It is chemically methyl morphine and is non-addictive. It is used in cough syrups to relieve chest pain.
- Morphine - It is a very powerful painkiller.
- Pethidine - Used in hospitals to tackle patients of severe pain like burn injuries, accidents, etc. It's addiction causes tremors in extremities and twitches in muscles.
- Methadone - It is used as a replacement drug for heroin.
- Heroin - It is chemically diacetyl morphine. It's withdrawal symptoms are severe as it is the most potent narcotic. WITHDRAWAL SYMPTOMS - Restlessness, excessive perspiration, chills, convulsions, episodes of criminal activity may follow.
- It stimulates our central nervous system.
- Source -tea, coffee, cocoa drinks (diuretic)
- Mode of action- It increases blood sugar level and alertness, relieves headache, and removes fatigue.
- However, excessive intake of tea or coffee leads to hyper acidity, pancreatic and kidney problems, insomnia. Tea intake after meals causes iron deficiency anaemia.
- These are speed uppers and hence commonly used party drugs (pep pills).
- Synthetic amphetamines are chemically alphamethyl phenyl ethylamines e.g. Benzidrine, Dexidrine, Methidrine.
- These are analogues of adrenaline and so are abused to avoid sleep, remove monotony, increase alertness and even to lose weight.
- Addiction symptoms - insomnia, headache, nausea, vomiting, talkativeness.
- Strongest stimulant and is alkaloid in nature.
- Source- its is obtained from the leaves and twigs of the plant Erythroxyllum coca.
- High dosage can cause hallucinogens.
- It actually inhibits re-uptake of dopamine (a neurotransmitter) at pre-synaptic membrane as a result of which accumulation of dopamine occurs in synaptic cleft that stimulates sympathetic system.
- Addiction symptoms include severe headache, insomnia, epileptic fits and may death may occur due to cardiovascular failure.
- It being a vasoconstrictor possesses anesthetic effect.
- NOVACAINE (Trade-name : PROCAINE) - it is a replacement for cocaine as it is non-addictive and is anesthetic in nature.
- Common names include : Princess, Big C, Coke.
- Crack - It is obtained by heating baking soda with cocaine and is furnished in the form of rods that are smoked
IV) HALLUCINOGENS (Psychedelic Drugs)
- Products of Hemp plant (Cannabis sativa) are known as cannabinoids, receptors for which are present in the brain.
- BHANG - It is obtained from fresh and dried leaves of male and plants.
- GANJA - It is dried female inflorescence.
- CHARAS (Hashish) - It is the resin obtained from female flowering tops.
- MARIJUANA - It is obtained from dried flowers and leaves of female plants.
- Active principle of cannabinoids is known as THC - Tetrahydrocannabinol.
- They increase appetite; stop ADH production and hence cause excessive urination (diuretic); spoil time sense; interfere with short-term memory; cause repetition of action; bring about hormonal imbalances and can induce sterility. They also cause dilation of pupils.
LSD - Lysergic Acid Diethylamide
- LSD is obtained from fruiting of Ergot fungus (Claviceps pupura).
- It is the strongest of all hallucinogens and causes CNS damage, chromosomal abnormality, foetal abnormalities, dilation of pupils and tachycardia (faster breathing rate).
- It is obtained from a cactus called Lophophora williamsii. The active principle it carries is anhalonin. It is hallocinogenic and causes vasospasm of cerebral arteries.
- It is obtained from the Mexican mushroom - Psilocybe mexicana. Its active principle is psilocin.