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DRUGS

Dr.CH.V.V.SATYANARAYANA MURTHY, M.Sc.,M.Phil.,Ph.D.Professor & HOD of Chemistry, Dept. of Chemistry

IDEAL INSTITUTE OF TECHNOLOGYVIDYUT NAGAR,KAKINADA-3.

Drug – Derived from French word “drogue” means a dry herb Drug may be defined as a substance used in the prevention, diagnosis, treatment or cure of disease in animals including man

Drug is a substance with an abnormal effect on certain body functions.

Disease is a Pathological process and its treatment with a drug ( a chemical compound or a mixture of chemical compounds) is a scientific process.

The science dealing with the action of drugs – Pharmacology

Characteristics of a Drug:

• The action of an ideal drug should be localized at the site where it is desired to act.

• It should be non-toxic.• it should have minimum side effects.• It should not injure host tissues or

physiological process• it should be efficient.• it should not make the host cells resistant to

the drug after its use for some time. 

History of Pharmacopoeia: Every country has legislation on Pharmaceutical preparations that sets standards and obligatory quality indices for medicaments, raw materials and preparations employed in the manufactures of drugs. These regulations are presented in separate articles – general and specific – relating to individual drugs, and are published in the form of a book called a Pharmacopoeia.Pharmakon-----drug or medicinePoieo------------to make The first British Pharmacopoeia (B.P.)---1864 U.S. Pharmacopoeia ( U.S.P.)-1820 I.P. Pharmacopoeia (I.P.) -1955

Storing of drugs under specific conditions:

1. cold -- between 20 and 80C.2. cool -- between 80 and 250C3. Room Temperature -- between 240 and 300C4. warm -- between 300 and 400C5. Excessive heat -- above 400C Whenever specific directions have been not given in the individual monograph, it means the storage conditions, which include protection from moisture, freezing and excessive heat.

1. Chemical synthesis --- 50%2. micro organisms --- 12%3. minerals --- 7%4.flowering plants(seed producing) --- 25%5. animals --- 6%

Sources of Drugs

Bacteria:

These are a group of micro-organisms which are unicellular and surrounded by rigid, complex, protein, cell wall.Gram +ve - retain the violet stain of grams reagentGram –ve - do not retain the stain of grams reagentGrams Reagent------Crystal violet + iodine

Virus:These are very small microorganisms which are

parasitic within living cells. These differ from bacteria in having only one kind of nucleic acid, either DNA or RNA. 

Absorption of drug:

A drug is its ability to reach the site where it is required , this is generally achieved by the process of absorption. Weakly acidic drugs -- absorbed more readily in the stomach. Weakly basic drugs -- absorbed more readily in intestine. 

SHELF LIFE OF DRUG

The expiration date or shelf-life of a drug product is defined as the time at which the average drug characteristic (e.g., potency) remains within an approved specification after manufacture (FDA, 1987). The United States Food and Drug Administration (FDA) requires that a shelf-life be indicated on the immediate container label of every drug product

The stability of drug and its dosage is of great importance for prediction of its shelf life. In traditional way, the drugs or dosages are normally conserved at room temperature and investigated until they lose their pharmacy effect. Therefore, the traditional method is really time consuming

The results obtained show that there is a correlation between pk (i.e. negative logarithm of rate constant of decomposition/evaporation process) and shelf life of the drugs . It is suggested that the shelf life of the drugs should be classified into the following 3 ranges in terms of their pk values and the initial temperature of thermal decomposition;

range I (pk7.0, and initial temperature T 450 K), the shelf life of drugs is between 1.5 and 2 years;

range II (pk < 12.0, and initial temperature T > 450 K), the shelf life of drugs is about 3 years;

range III (pk > 12.0, and initial temperature T was not defined at present yet), the shelf life of drugs is between 4 and 5 years.

Antimalarials:

It is characterized by periodic fever, anemia and enlargement of liver and spleen.

In human being it is caused by the few species of plasmodium when an infected female anopheles bites to the man. I.e., actually first of all the Plasmodium Protozoan infects female anopheles which then infects the human.Chloroquine derivatives are most widely used.

General Anaesthetics:

Anaesthesia means insensibilityThose drugs which produce insensibility to the

vital functions of all types of cells especially those of the nervous system.

The effect produced by an anaesthetic is reversible, which means that the effected organs return to the normal state as soon as the concentration of the anaesthetic is decreased. 

Characteristics: •It should be inert•It should be potent and nonflammable•it should be non-irritating to mucous membranes.•it should produce not only anaesthesia but also analgesia and muscle relaxation.•it should not produce severe hypo tension•it should be non-toxic to brain, liver, heart and kidney.•it should not produce nausea or vomiting.

Classification:

General anaesthetics: These depress the central nervous system to such an extent that all sensitivity to pain or feeling is lost, i.e., they produce unconsciousness all over the body.

Local anaesthetics:

These do not effect the whole body but make a part of the body insensitive to pain or feeling.

Hypnotics are central nervous system depressants that produce sleep to reduce restlessness and emotional tensions.

The patient cannot be easily awakened until the effect of the hypnotic wears out.

Sedatives are also central nervous system depressants that reduce restlessness and emotional tension without producing sleep.

AnaesthesiaSedation Hypnosis Coma Death

Hypnotics and Sedatives

Anticonvulsant drugs:

The drugs used in the treatment of various types of epilepsy are called anticonvulsant drugs.

Epilepsy is a disease which arises due to central nervous system disorders.

Antiseptics:

Antiseptics are those chemical compounds which prevent the sepsis of wounds, i.e., stops the action of microorganisms either by inhibiting their reproduction or causing their death.

Disinfectant kills the organisms outrightly.

An antiseptic action is milder but more prolonged while a disinfectant action is immediate but is of short duration.

Antituberculosis drugs:Tuberculosis, the oldest fatal disease, is a

systematic infectious disease caused in man by Mycobacterium tuberculosis and Mycobacterium bovis.

Athough tubercle bacilli may effect any organ or tissue in the body, but lung is the most common effected organ.

The disease may vary in intensity from the latent tuberculosis to the acute generalized tuberculosis.

A drug used for treating the tuberculosis is known as anti-tubercular drug.

Anti-Leprotic drugs:

Leprosy is a disease caused by Myco bacterium Leprae, which cause characteristic lesions in the skin and the peripheral nerves.

Plonged intimate contact for some years cause leprosy lesions.

Its development takes many years to become apparent, it needs prolonged drug therapy. 

Anticancer agents(Antineoplastics drugs):

It is a type of tumor which means an unusual amount of growth or enlargement of a tissue due to uncontrolled and unlimited repeated divisions of some cells.It can develop after the age of 30 to 40 years.Very rapid growth after the age of 45 to 50 years

Cancer may cause due to sudden alterations in one or more chromosomes, or change occurs in Cytoplasm.

Categories:

Non-malignant: It does not spread to other part of the body and is removed by operation.

Malignant: It spreads all the neighbouring tissues like the roots of the tree. In last stage tumour growth bursts and cancereous cells migrate to other parts of the body through the blood stream—metastasia --- causes death.

Cancer-causing agents

1.Heavy smoking.2.chewing of pan or tobacco.3. constant chronic physical irritation of tissue.4. constant touch of carcinogenic compounds5. x-rays, UV-rays and other ionizing radiations.

Cancer therapy:

1.Surgery: Cancerous cells are dislodged during operation.

2. Radiotherapy: For checking and destroying the cancerous growth

3. Chemotherapy: For producing temporary relief from pain, for increasing survival time and for decreasing the rate of spreading of the cancerous growth.

Tranqkuilisers:

Tranquilisers are drugs which are employed in the treatment of mental disorders.It restores the peace of mind without producing sleep.

Cardiovascular drugs:

Drugs having direct action on the heart or other parts of the vascular system and they modify the total output of the heart or the distribution of blood to certain parts of the circulatory system.

Diuretics:

Substances that increase the output of urine by the kidneys are called diuretics are used for increasing the excretion of sodium and chloride ions in patients suffering from edema.

Edema: disease associated with abnormal retention of salt and water in the extracellular parts of the body. 

Antipyretics and Analgesics:

Antipyretics---- Substances which reduce body temperature in fever.

It effects the hypothalamine center which in turn activates the dilation of the peripheral blood vessels and increases the rate of perspiration which causes the body to loose heat and subsequently lowers the body temperature.

Analgesics----Compounds which relieve pain

Anticoagulants:In the normal condition the blood is in the fluid state

and hence it can circulate very easily, through the blood vessels. But sometimes to which we call abnormal state the blood in the vascular system is clotted under the influence of some substance.

The clotting or coagulation of blood interferes in its circulation which leads to serious result ultimately death.

Clotting of blood is completely a biochemical process.

In normal conditions the coagulation of blood in the vascular system is prevented by an organic subsance, heparin, produced in liver.

Drugs used in Diabetes:

Diabetes mellitus, the most common metabolic disease, is caused by lack of insulin.

Insulin—transport of glucose into cells.

Deficiency of insulin—build up of glucose in the blood and a deficiency of the necessary glucose in the cell.Pancreas---- release of insulin

Tolbutamide--- stimulate the secretion of insulin from pancreas. 

Antibiotics ( Antibacterial Agents)

Humans, and our domestic animals, can serve as hosts to a wide variety of disease-causing organisms (pathogens): •Bacteria •Viruses•Fungi•Protozoans•Helminths(worms).

There are many chemicals that are lethal to bacteria

•Semi-synthetic products

•Completely synthetic products

•Natural products

Don't use an antibiotic to treat a viral disease (e.g., a cold) for which antibiotics are useless.

However, doctor may prescribe an antibiotic if you are infected by an influenza virus — not to fight the virus but to protect you against a secondary bacterial infection of your damaged lungs.

Don't save unused antibiotics for later self-medication.

DRUGS AND ALCOHOL 

The effects of drugs can make two people taking exactly the same drug behave in different ways

Why do some drug users become addicted, while others don’t?As with many other conditions and diseases, vulnerability to addiction differs from person to person. Your genes, mental health, family and social environment all play a role in addiction.

Risk factors that increase your vulnerability include:• Family history of addiction• Abuse, neglect, or other traumatic experiences in childhood• Mental disorders such as depression and anxiety• Early use of drugs• Method of administration—smoking or injecting a drug may increase its addictive potential

DRUG EFFECTS

Drugs are split into four main groups:

Stimulants increase heart rate, making you chatty and confident. They can also put a lot of strain on the heart. Users can become depressed after using stimulants.

Depressants slow down the heart rate, making users feel relaxed. They can also make users feel depressed, drowsy and unable to concentrate.

Hallucinogens users see things in vivid colours and often see things that aren't really there. The feelings from these drugs can be very intense, and can make you very giggly and 'drunk'. Painkillers numb the senses, and can make people feel better. They can be very addictive..

Alcohol gets into your bloodstream so the effects can be almost immediate, but it can take hours to wear off depending on your size, weight, what you are drinking, how strong it is and how much you drink.

Bad judgement, poor memory

infection

Alcoholic hepatitis

urinary infections

internal bleeding

Brittle bones

Lack of co-ordination

Impaired vision and hearing

Cancer

stroke

Weakened InflammationLack of co-ordination

Impaired sexual performance,low sperm count

APPROXIMATE VALUES FOR DETECTION PERIODS

Substance Urine Hair Blood

Alcohol3–5 days via Ethyl Gluconoride(EtG) metabolite or 10–12 hours via traditional method

up to years 12 hours

Barbiturates (except phenobarbital)

2 to 3 daysup to 90 days

1 to 2 days

Phenobarbital 7 to 14 daysup to 90 days

4 to 7 days

Cocaine 2 to 4 daysup to 90 days

24 hours

Codeine 2 daysup to 90 days

12 hours

Cotinine (a break-down product of nicotine)

2 to 4 daysup to 90 days

2 to 4 days

Morphine 2 daysup to 90 days

6 hours

Heroin 2 daysup to 90 days

6 hours