Shit i dont know Flashcards
Organ Specific Autoimmune conditions
Hashimoto’s Thyrotoxicosis Primary myxoedema Chronic atrophic gastritis Pernicious anaemia Addison’s Disease Myasthenia gravis Diabetes mellitus (type 1)
Intermediate / Mixed Autoimmune conditions
Goodpasture’s syndrome
Primary biliary cirrhosis
Autoimmune haemolytic disease
Ulcerative colitis
Non-Organ specific Autoimmune conditions
Systemic Lupus Erythematosus
Rheumatoid arthritis
Sjogren’s syndrome
Progressive systemic sclerosis
Oral Bioavailability Equation from graph
Oral Bioavailability =(AUC oral)/(AUC IV) × 100
Components of First Pass Metabolism
The Gut Lumen
Gastric acid, proteolytic enzymes, grapefruit juice
The Gut Wall
P-glycoprotein efflux pumps drugs out of the intestinal enterocytes back into the lumen, e.g. cicosporin
The Liver
Substances absorbed in the ileum enter the portal circulation and are taken to the liver, where enzyme systems metabolise them
`Volume of Distribution equation
Volume of Distribution= (Total Amount of Drug in Body)/(Plasma Concentration of Drug at time zero)
Body distribution VOD values estimate
When the volume of distribution is less than 5 Litres, it is likely that the drug is restricted to the vasculature.
If it is less than 15 Litres, this implies that the drug is restricted to the extracellular fluid
Greater than 15 Litres suggests distribution within the total body fluid.
Some drugs (usually basic) have a volume of distribution that exceeds body weight, in which case tissue binding is occurring
Phase II metabolism, most common conjugates and requirements
The reactive intermediate from Phase I is conjugated with a polar molecule to form a water-soluble complex. The process is also known as conjugation.
Glucoronic acid is the most common conjugate, as it’s an available by-product of cell metabolism. Drugs can also be conjugated with sulphate ions and glutathione.
Phase II metabolism requires specific enzymes and a high-energy cofactor, uridine diphosphate glucuronic acid (UDPGA).
Half Life equation
Half Life= (0.693 × Volume of Distribution)/Clearance
Rate of Metabolism equation
Rate of Metabolism=(Vmax [C])/Km
Steady State Concentration in Plasma (CpSS) equation
Steady State Concentration in Plasma (CpSS)= (Dose Rate)/Clearance
Loading Dose equation
Loading Dose (Dose L)= Vd ×CpSS
Common drug drug interaction drugs
Anticonvulsants
Phenytoin
Carbamezepine
Anticoagulants
Warfarin
Antidepressants
Monoaimine Oxidases
Antibiotics
Rifampicin
Macrolides
Quinolones
Antiarrhythmics
Amiodarone
Enzyme involved in warfarin metabolism
Warfarin – CYP2C9
Enzyme involved in codeine metabolism
Codeine – CYP2D6