ROUTES OF ADMINISTRATION Enteral route Inhalation is through

ROUTES OF ADMINISTRATION

Enteral route Inhalation is through the alimentary canal. It might be: Hypospray or jet injections Oral Sublingual Per rectum Parenteral route Injections: Intra muscular Intra venous Intra-arterial Intradermal Subcutaneous route (Hypodermic) Inhalation may be the route of choice to avoid the systemic effects. In this way drugs can pass directly to the lungs. Drugs used involve volatile drugs and gases. Examples include aerosols like salbutamol; Topical may be applied to the external surfaces, the skin and the mucous membranes. Topical route includes:

ORAL Advantages: It is convenient It is the cheapest available route It is easy to use It is safe and acceptable. Disadvantages: Less amount of drug reaches the target tissue. Some of the drug is destroyed by gastric juices e. g. adrenaline, insulin, oxytocin Absorption has to take place which is slow, so is not preferred during emergency. It might cause gastric irritation It might be objectionable in taste. It might cause discoloration of teeth e. g. iron causes staining, tetracyclines below 14 cause brown discoloration so are not advisable during pregnancy.

DISADVANTAGES Slow Some risky interaction with certain foods increase toxicity Vomiting Some drugs too quickly become metabolised by the liver and become ineffective Some effects irreversible

Rectal Route: Drugs in solid forms such as suppositories or in liquid forms such as enema are given by this route. Drugs may have local or systemic actions after absorption

INJECTION Injection encompasses intravenous(IV), Intramuscular(IM), and subcutaneous (subcut) Advantages Fast, 15 -30 seconds for IV, 3 -5 minutes for IM and subcutaneous (subcut) Greatest effect Suitable for drugs not absorbed by the digestive system or those that are too irritant One injection can be formulated to last days or even months, e. g. , Depo-Provera, a birth control shot that works for three months.

Injection is a way of getting a liquid drug in to the body using a needle and syringe, usually intravenously (injecting in to a vein), sometimes intramuscular (injection in to a muscle) or subcutaneous (just below the skins surface, known as skin popping). The full effects of the drug are experienced very quickly and intensely as it gets the drug directly into the bloodstream and on to the brain. All methods of injecting are potentially extremely harmful - of all the ways to get drugs into the system, injection has the most risks by far as it bypasses the body's natural filtering mechanisms against viruses, bacteria and foreign objects. There is a greater risk of overdose, infections and health problems.

Which drugs are injected? There are very few drugs which cannot be injected. Heroin is the best known but all the opioids and opiates can be injected as can the stimulants amphetamines and cocaine and almost any drug which comes in tablet or capsule form. Cannabis is very difficult to inject.

How are drugs prepared for injection? Some drugs come in ampoule form ready for injection either as a liquid or sometimes as a powder to which sterile water can be added. Other drugs come as tablets or capsules which are then crushed or broken open and the contents mixed with water to make a solution ready for injection. One of the tranquilliser drugs, Temazepam is produced in a gel filled capsule which is sometimes heated by drug injectors prior to injecting the warmed up liquid. Other drugs, particularly heroin, amphetamine and cocaine are usually supplied as powders of varying consistencies and purities which need to be prepared for injection. - See more at:

DISADVANTAGES

INHALANTS

INHALATION Advantages Fast Method, 7 -10 seconds for the drug to reach the brain Disadvantages Typically an addictive route of administration because it is the fastest, leading to instant gratification. In addition, drugs taken this way do not stay in the bloodstream for as long, causing the user to redose more quickly and intensifing Difficulties in regulating the exact amount of dosage

Powders and crushed up tablets need to be prepared by first of all mixing with water. 'Brown' street heroin will also need citric or ascorbic acid to be added in order to help it dissolve. Unless the drug concerned is very pure it will also be necessary to filter out the impurities, chalk and other dust which may be mixed in with the drug. -

ACROSS MUCOUS MEMBRANES Advantages Low risk Convenient No paraphernalia required Fairly quick effect

DISADVANTAGES Only for fat soluble drugs Lack of ritual Boring

TOPICAL Drugs may be applied to the external surfaces, the skin and the mucous membranes. Topical route includes When the drug is applied to the outer skin, it is called enepidermic route of drug administration.