THERAPEUTIC DRUG MONITORING Flashcards
- Involves the analysis and evaluation of circulating concentrations of drugs in blood
THERAPEUTIC DRUG MONITORING (TDM)
- To ensure that a given drug dosage produces maximal therapeutic benefit and minimal toxic adverse effects
THERAPEUTIC DRUG MONITORING (TDM)
INDICATIONS OF TDM
- Consequences of [?] are serious
- Narrow [?]
- Good correlation between circulating concentrations and [?]
- Change in [?] that may affect circulating drug concentrations
- Occurrence of [?]
- Monitoring [?]
over- and under-dosing
margin of safety
therapeutic or toxic effects
patient’s condition
drug interactions
patient compliance
- The rate at which the drug is absorbed is dependent upon the route of administration
ABSORPTION
require dissolution
- Tablets & capsules
are rapidly absorbed
liquids
- Transport mechanism:
passive diffusion
- Weak acids are absorbed in the [?] ; weak bases in the [?]
stomach
intestine
Crucial step in obtaining accurate and meaningful results
Single most important factor :
timing
Peak concentrations:
1 hour after an orally administered dose (1-hr post-dose)
Type of sample/sample matrix:
• Serum or plasma – typically used
• Heparin – commoly used anticoagulant
Avoid any degree of [?]– affects conc of elements;
proper phlebotomy techniques, gentle mixing
hemolysis
[?] of sample is important
Prompt processing
may be collected overtime to asses blood level at different points in the dosing interval
Multiple samples
(provides more comprehensive picture in the drug exposure and aids in dosage adjustment)
Multiple samples
Maintain [?], including choice of anticoagulant and collection techniques
consistency in collection
• Used to treat congestive heart failure and cardiac arrhythmias
CARDIOTROPICS
• Act on the conduction system of cardiac muscle
CARDIOTROPICS
• Net effect: slow down electrical conduction
CARDIOTROPICS
- for supraventricular and ventricular arrhythmias
Quinidine
Procainamide
Cinchonism
Quinidine
Quinidine Common formulation:
Quinidine sulfate & Quinidine gluconate
- for supraventricular or ventricular arrhythmias
Quinidine
Procainamide
Procainamide Metabolite :
n-acetylprocainamide
Reversible lupus-like syndrome w/ elevated ANA titers, urticaria, rash, agranulocytosis and nephrotic syndrome
Procainamide
- local anaesthetic
Lidocaine
- acute control & prevention of ventricular arrhythmias after MI
Lidocaine
- convulsions, coma, respiratory depression, bradycardia, hypotension
Lidocaine
- a short-term prophylactic agent in brain injury
Phenytoin (Dilantin)
- Toxicity is seen at the level of the therapeutic range
Phenytoin (Dilantin)
Major toxicity: initiation of seizures
Phenytoin (Dilantin)
Other toxic effects: hirsutism, gingival hyperplasia, Vit. D & folate deficiency
Phenytoin (Dilantin)
- Antagonizes effects of epinephrine on the heart, arteries and arterioles of skeletal muscles and on the bronchus
Propranolol
- causes vasodilation
Propranolol
- used for treatment of hypertension and angina pectoris
Propranolol
Verapamil
- for life-threatening ventricular arrhythmias
Amiodarone
- angina, hypertension, supraventricular arrhythmias
Verapamil
Treatment of gram (-) bacterial infections
AMINOGLYCOSIDES
Toxic effects: nephrotoxicity and ototoxicity
AMINOGLYCOSIDES
VANCOMYCIN
Administered IM or IV
AMINOGLYCOSIDES
PHENYTOIN
Effective against gram (+) cocci & bacilli
VANCOMYCIN
Administered by IV infusion and orally
VANCOMYCIN
Toxic side effects occur in the therapeutic range (5 - 10 ug/mL)
VANCOMYCIN
Trough levels are monitored
VANCOMYCIN
Toxic effects: “red-man syndrome” nephrotoxicity and ototoxicity
VANCOMYCIN
Characterized by erythematous flushing of the extremities
RED MAN SYNDROME
TYPES OF SEIZURE
1. Focal/Partial Seizure
a. Simple Partial
b. Complex partial
TYPES OF SEIZURE
2. Generalized
a. Tonic-Clonic (Grand Mal Seizure)
b. Absence Seizure (Petit Mal Seizure)
c. Myoclonic Seizure
d. Atonic Seizure
• originates in one specific area of the brain and will not cause loss of consciousness
Simple Partial
• symptoms may vary, but may include altered emotions, sensory changes, or motor symptoms
Simple Partial
• originates in one specific area of the brain and will lead to loss of awareness/consciousness
Complex partial
changes in behaviour, automatic movements, and confusion
Complex partial
• Muscle stiffening
(Tonic)
• Rhythmic jerking of the limbs
(Clonic)
• Most common seizure
Tonic-Clonic (Grand Mal Seizure)
• sudden loss of consciousness
Tonic-Clonic (Grand Mal Seizure)
• Brief episode of starring/absence/blanking
Absence Seizure (Petit Mal Seizure)
• Often mistaken for daydreaming
Absence Seizure (Petit Mal Seizure)
• Typically seen in children
Absence Seizure (Petit Mal Seizure)
• Involuntary jerking/twitching of muscles
Myoclonic Seizure
• Affects specific muscle groups or the entire body
Myoclonic Seizure
• Sudden loss of muscle tone leading to a person collapsing
Atonic Seizure
Generalized tonic-clonic seizures and simple partial seizures
PHENOBARBITAL
Toxicity :
• Nystagmus
• Ataxia
• Stupor
• Respiratory depression
• Hypotension
• Coma
PHENOBARBITAL
• short-term prophylactic agent in brain injury
PHENYTOIN
• Major toxicity: initiation of seizures
PHENYTOIN
Other toxic effects:
• Hirsutism
• Gingival hyperplasia
• Vit. D & folate deficiency
PHENYTOIN
PHENYTOIN Injectable proform:
Fosphenytoin
• Used for treatment of petit mal & absence seizure
VALPROIC ACID
ETHOSUXIMIDE
• Enhance the activity of Gamma Amino Butyric Acid-mediated inhibitory system
VALPROIC ACID
• Hepatic dysfunction: hyperammonemia
VALPROIC ACID
• Teratogenic effects
VALPROIC ACID
• Toxicity: sedation, gastric disturbances, ataxia
VALPROIC ACID
• Generalized tonic clonic, simple partial and complex partial seizures
CARBAMAZEPINE
PRIMIDONE
• Tic douloureux (trigeminal neuralgia)
CARBAMAZEPINE
• Reduction of excitatory synaptic transmission in the spinal trigeminal nucleus
CARBAMAZEPINE