This document discusses key principles of pharmacokinetics including drug absorption, distribution, metabolism, and elimination. It provides examples of drugs that require therapeutic drug monitoring for several disease states, such as digoxin for cardiovascular issues, aminoglycosides for infectious diseases, and theophylline for pulmonary conditions. The document also outlines factors that influence pharmacokinetic parameters like body size, age, disease state, and drug interactions. Equations for calculating pharmacokinetic measures like loading dose, maintenance dose, and drug clearance are presented.

2. LIBERATION DOSAGE FORM, STABILITY, QU
ABSORPTION ROUTE, DOSE
DISTRIBUTION DRUG TARGET, EFFICACY
METABOLISM HALF-LIFE, SAFETY
ELIMINATION DURATION, FREQUENCY

3. Cardiovascular : Lidocaine, procainamide, digoxin
Infectious Disease: Aminoglycosides, vancomycin
Neurology:
Phenytoin, carbamazepine, phenobarbital, valproic acid
Oncology: Methotrexate
Pulmonary: Theophylline, aminophylline
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Transplant: Cyclosporine, tacrolimus, sirolimus

4.  Intravenous: X0 = C0/Vd
 Single IV: Ct future = C0* e-ket
Ct past = C0 / e-ket
 Multiple IV: Dose= (Cp *Vd)(1-e-nkeτ /1-e-keτ)e-ket
 Short-term Infusion (0.5 h), Multiple Dosing:
› R0= CL*Cmax{1-e-keτ /1-e-keT} e-ket 1
› Cmin= Cmax*e-ke(τ -T)
 Continuous Infusion (1 h):
› R0= CL*Cpss*[1-e-keτ]/1-e-keT 1 ] e-ket 1
› Cmin= Cpss*e-ke(τ -T)
› 2R0/(C1+C2) + 2Vd (C1-C2) )/(C1+C2) (t1-t2)
 Loading Dose: LD = Vd*Css / SF
 Intermittent IV Bolus: Dose/τ = CL*Cp{1-e-keτ/1-e-keT}*e-ke(τ -T)
 Maintenance Dose: MD =CL*Css* τ / SF
 Oral:
› Multidose: Cave steady state = [LD/Vd*(1-e-keτ)] Ansel. Dosage Forms.
› Dose = C*(ka-ke)*Vd/SF*ka* (e-ket-e-kat)
 Steady State: Multiple doses cause term 1-e-nket 1
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5. Loading Dose 25 mg/kg IBW DIGOXIN Ht
Maintenance Dose 19 mg/kg
VANCOMYCIN
Creatinine Clearance
AMINOGLYCOSIDES
A review of clinical use of theophylline in acute asthma: Factors influencing kinetic disposition and drug interactions
Ohnishi, A./Methods Find Exp Clin Pharmacol 2000, 22(4): 253
ISSN 0379-0355 Copyright 2000 Prous Science CCC: 0379-0355 DOI: 10.1358/mf.2000.22.4.584459
THEOPHYLLINE Rxkinetics.org

6. 1. Body Compartment: Central vs Peripheral
2. Body Surface Area
3. Weight & Body Composition
• Actual body weight – All Tissues
• Ideal body weight - Muscle
• Adjusted body weight – Intermediate Distribution
4. Adjustments to PK:
• Age
• Gender
• Disease
• Food
• Drug Interactions
5. Clinical Endpoint, Surrogate Marker, Lab Measures
6. Toxicity

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8. Images as noted and courtesy of Wikipedia Commons