Rx Note

Introduction Physiological and biochemical exists to protect the eye from harmful stimuli. Tears contain lysozymes and immunoglobulins, which impart an anti-infectious activity. While these mechanisms are protective, they do sometimes present to drug absorption. The tear volume in the normal is 5-9 µL. Basal tears are continuously secreted by the lacrimal glands at an average rate of 1.2 µL/min, thus giving a tear turnover rate of approximately 17% per minute. Reflex tears are triggered by irritants, and their secretion rate ranges from 3 to 400 µL/min, the intention being rapidly to eliminate the stimulus. Another protective mechanism is the eyelid movements associated with blinking. Blinking moves tear fluids and foreign matter to the nasal corner of the lid surface, where the liquid exits via the puncta and is then drained away by the nasolacrimal ducts into the inferior nasal passage - often called the lacrimal pump Topical ophthalmic preparations are medications applied directly t...

Introduction The absorption pattern of drugs differs considerably between individual drug substances, as well as between the different administration routes. A medication administration route is often classified by the location at which the drug is administered, such as oral or intravenous. The choices of routes in which the medication is given depends not only on the convenience and compliance, but also on the drug's pharmacokinetics and pharmacodynamic. The right route of administration and dosage form is selected to maximise outcome of treatment. To illustrate, 32 years old epileptic male with fever and infection on nasogastric feeds , prescribed with phenytoin 300 mg daily. Which dose form do you choose (capsules, suspensions or injections) and why? 48 years old patient with osteomyelitis, microbiological culture positive for the bacteria Methicillin Resistant Staphylococcus Aureus (MRSA). Which dose form do you choose (IV or oral) and why? 4 years old boy diagnosed with bron...