DRUGSDRUGS

Mrs. Zubda Atta

Drugs:Drugs:

Any substance taken into the body that modifies or affects chemical reactions in the body.Orally, by injection, applied as cream or inhaledMedicinal drugs:

Antibiotics – treat bacterial infections

Anaesthetics – cause numbness or loss of sensation; body unable to feel painAnalgesics – relieve pain without causing numbness of affecting consciousness; do not cure disease; aspirin

Types of drugs and their mode of action:Types of drugs and their mode of action:

Antibiotics:Antibiotics:

A chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections.Alexander Fleming – 1928 – penicillin; penicillium notatumSome act by disrupting the production of cell wall and so prevent reproduction or even cause them to burst open; some interfere with protein synthesis thus arrest bacterial growth.Animal cells do not have cell walls and structures involved in protein synthesis are different – do not damage human cellViruses have no cell walls so are unharmedSome bacteria may evolve to become resistant to a particular antibiotic – selection pressure

Drug abuse – misuse of drugs:Drug abuse – misuse of drugs:

It is taking of drugs excessively, or not under a doctor’s prescriptionDrug abuse can cause:

Tolerance – you have to keep taking more and more of a drug to achieve the same effect as experienced initiallyAddiction or dependence – if a person does not take the drug they experience withsrawl symptoms. They become:

physically ill (nausea, vomiting etc.)mentally disturbed (acute anxiety,

depression etc.)

Heroin – addictive depressant:Heroin – addictive depressant:

Opium from opium poppies contain chemicals – morphine and codeine are used in medicine for pain reliefHeroin is made from morphine – also medicine but addictiveAlso depressant – slows down many functions of brain – reduces pain and slows down breathing; slows down function of hypothalamusGives a feeling of euphoria – intense happiness; quick addictionAs body becomes tolerant they increase dosage to avoid withdrawal symptoms and accidental overdoses result in deaths.As a result person is unable to be a part of normal society, unable to hold down a job leading to crime, unable to support family.Taken by injecting in veins – AIDSCure – will power, rehabilitation centers

Immediate effects: dulls the senses, gives sense of well being, reduces hunger, relieves tension, make drowsyLong term effects: brain damage, lung damage, serious weight loss, withdrawal symptomsWithdrawal symptoms may include anxiety, sweating, vomiting, diarrhea, convulsions, hallucinations, in severe cases death

Alcohol:Alcohol:

Ethanol – found in alcoholic drinks – powerful drugMake people relaxed, release their inhibitions, reduces tension, making it easier for them to enjoy and mix and interact with other peopleQuickly absorbed into blood through wall of stomach – broken down by liver – about 10 cm3 an hour so rest circulates in blood Depressant – even small amounts slow down actions of parts of brain so lengthens the time you take to respond to a stimulus – road accidentsMany countries have legal limits on blood alcohol level when you drive.In some people it increases aggression and release their inhibitions causing them to be violent and to commit crimesResearch shows 50 % of home violence is alcohol related and 60 % criminal behavior.

It is a poison – large intakes can result in unconsciousness, coma and even deathSometimes death is caused by vomiting when unconscious – suffocation from vomit blocking the airwaysAlcoholism – a person cannot manage without alcohol – factors may include genes, personality and amount of stressLong term affects:

Alcohol is poisonous to cells – liver damage – cirrhosis (fibres grow in liver)Also damage brain – loss of memory, confusionOne way of damage is alcohol in body fluids draws water out of body cells; if brain cells shrink they are irreversibly damagedOsmotic effect is made worse as alcohol inhibits release of hormone that stops kidneys from allowing too much water to leave the body in urine – hence low levels of water in blood

Smoking:Smoking:

Dangerous to both smokers and non smokers – passive smokingNicotine:

Stimulant – affects brain – makes a person more alertThen relaxes the muscles and later dulls the brain and sensesAddictiveMake blood vessels get narrower increasing blood pressure leading to hypertension. This increases risk of developing heart disease – also because it causes release of adrenaline that increases heart beat and blood pressure.It makes blood clot easily – heart attack or brain stroke

Tar:Brown sticky substance that collects in lungsContains many chemicals some are carcinogens – affect behavior of some cells in respiratory passage and lungs causing them to divide uncontrollably – tumor – malignant than cancerCells may break away from tumors and spread to other body partsAll types of cancers are more common in smokers than in non smokersIt affects mucus membranes – the person coughs to clear the vessels

Carbon monoxide:Poisonous gas – diffuses from the lungs into blood and combines with haemoglobin. Less oxygen can be carried and so body cells are deprived of oxygenMother smokes, baby gets all harmful chemicals in blood that prevent it from growing properly.It damages the lining of blood vessels and increase the tendency of blood to clotIt also increases the rate at which fatty substances are deposited on inner walls of arteries causing lumen to become narrow (atherosclerosis)

Smoke particles:Little particles of carbon and other materials that get trapped inside lungsWBC try to remove them and secrete chemicals that instead do serious damage to lungsThe irritants in smoke stop the cilia from beating and weaken the walls of alveoliThe irritate the cells lining the air passages causing production of mucus that causes smokers cough. The coughing bursts the walls of alveoli Eventually gas exchange surfaces in lungs are reduced leading to emphysemaDifficult to get enough oxygen to blood – no energy