Drug interactions and adverse effects

Drugs are chemical substances that cause changes in organisms’ physiology or psychology when consumed. They chemical substances used to treat, prevent, and/or ameliorate diseases. Drug interactions Drugs interact in a number of ways that may produce unwanted effects. Two types of interactions exist: pharmacodynamic and pharmacokinetic. Pharmacodynamic interactions Pharmacodynamic interactions involve a direct conflict between the …

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Pharmacokinetics of drugs and drug substances

Pharmacology can be divided into two disciplines. These are: Pharmacokinetics: the way the body affects the drug with time, i.e. the factors that determine its absorption, distribution, metabolism and excretion. Pharmacodynamics: the biological effect of the drug on the body. 1. Administration Topical Topical drugs are applied where they are needed, giving them the advantage that …

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Drug receptor interactions

Most drugs produce their effects by acting through specific protein molecules called receptors. Receptors respond to endogenous chemicals in the body that are either synaptic transmitter substances (e.g. ACh, noradrenaline) or hormones (endocrine, e.g. insulin; or local mediators, e.g. histamine). These chemicals or drugs are classed as: Agonists: Activate receptors and produce a subsequent response. Antagonists: Associate with …

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Molecular basis of pharmacology

What is pharmacology? Pharmacology is the study of the actions, mechanisms, uses and adverse effects of drugs. A drug is any natural or synthetic substance that alters the physiological state of a living organism. Drugs can be divided into two groups: Medicinal drugs: substances used for the prevention, treatment and diagnosis of disease. Non-medicinal (social) …

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Drug factors in dosage form design

Each type of dosage form requires careful study of the physical and chemical properties of drug substances to achieve a stable, efficacious product. These properties, such as dissolution, crystal size and polymorphic form, solid-state stability and drug– additive interaction, can have profound effects on the physiological availability and physical and chemicals tability of the drug. Through …

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Route of drug administration in humans and animals

The absorption pattern of drugs differs considerably between individual drug substances, as well as between the different administration routes. Dosage forms are designed to provide the drug in a suitable form for absorption from each selected route of administration. The following discussion considers briefly the routes of drug administration and, whilst dosage forms are mentioned, this is …

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Principles of dosage form design

Drugs are rarely administered as pure chemical substances alone and are almost always given as formulated preparations or medicines. These can range from relatively simple solutions to complex drug delivery systems through the use of appropriate additives or excipients in the formulations. The excipients provide varied and specialized pharmaceutical functions. It is the formulation additives …

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