National Nursing Review : Nursing Study Resources & Health Tips

Few drugs, if any, have absolute specificity, but most features on selectivity, eg., Atropine inhibits the action of acetylcholine on smooth muscle and exocrine glands, but not the skeletal muscle. The selective action of these drugs is due to their physical-chemical bond with cellular components known as receptors. The receptors are physiological molecules involved in transmitting chemical signals between a cell and another and within cells. A molecule that binds to a receptor is defined ligand. When a ligand (hormone, neurotransmitter, drug or intracellular messenger exogenous) combines with a receptor cell function is changed, each ligand can interact with multiple receptor subtypes. The receptors activated directly or indirectly regulate cellular biochemical processes (eg., Ion conductance, protein phosphorylation, transcription of DNA). In many cases, the receptors located within the cell membrane are coupled through the guanine nucleotide binding proteins (G proteins) with different effector systems involving molecules that act as intracellular second messengers.

The receptors are dynamic structures, affected by both external factors and by intracellular regulatory mechanisms. The up-regulation and down-regulation of receptors relate phenomena of adaptation to drugs which have important clinical implications (desensitization, tolerance, acquired resistance, hypersensitivity to suspension).

The specific regions of macromolecules molecular receptor which binds the ligand recognition sites are called. A drug may interact at the same site which interacts with an endogenous agonist (hormone or neurotransmitter) or at a different site. Agonists that bind to adjacent sites or different allosteric agonists are sometimes called. The drugs are also linked in a non-specific, ie not at the molecular features of sites like receptors (eg., Plasma proteins). (more…)

Some people experiment with prescription drugs because they believe that will help even more fun, lose weight to fit into a certain group and even to study better. Prescription drugs can be achieved more easily than illicit drugs: it is likely that a family member or friend has a prescription. But in some cases, prescription drugs are sold on the street like other illegal drugs.

But prescription drugs are only safe for people who have been prescribed. This is because a doctor has examined these people and know they will not have adverse drug reactions. The doctor also told them exactly how to take the medication and what to avoid while you take: as alcohol, tobacco or other drugs.

Canadian Prescription drugs that are used most often are classified into three categories:

Opioides
Examples: oxycodone (OxyContin), hydrocodone (Vicodin) and meperidine (Demerol).
Medical uses: Opioids are used to treat pain or relieve coughs or diarrhea.
How they work: Opioides attach to opioid receptors in the central nervous system (brain and spinal cord) and prevent the brain from receiving pain messages. (more…)

Medication: Any substance or combination of substances for treating or preventing disease in human, as well as product out that can be administered to humans or animals to establish a diagnosis or to restoring, correcting or modify their functions.
Whatever its form combines a drug:
An active (therapeutic)
A vehicle (no action against the disease, support the active ingredient)
With an adjuvant (facilitates the implementation, administration, or retention of the drug).
The origins of drugs:
A plant (herbal)
Ä animal (opotherapy)
Ä mineral (trace element, mercury, …)
Ä microbial origin (antibiotics, vaccines, …)
Ä synthetic origin (chemotherapy, …)
Ä biotechnological origin (laboratory, biogenetic engineering, …). (more…)

Mechanisms of Action
Steroids alter the synthesis of proteins therefore alter:

• Chemotaxis,
• Metabolism
• Expression (hormones, mediators).

Pharmacological Actions

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