Warfarin (Coumadin):

• The most common oral anticoagulant.
• It is only active in vivo.
• Warfarin is almost completely bound to plasma proteins. -96% to 98% bound.
• Warfarin is metabolized by the liver and excreted in the urine.
• Coumarin anticoagulants pass the placental barrier and are secreted into the maternal milk.
• Newborn infants are more sensitive to oral anticoagulants than are adults because of lower vitamin K levels and lower rates of metabolism.

• Bleeding is the most common side effect and occurs most often from the mucous membranes of the gastrointestinal tract and the genitourinary tract.

Oral anticoagulants are contraindicated in:

• Conditions where active bleeding must be avoided, Vitamin K deficiency and severe

hepatic or renal disease, and where intensive salicylate therapy is required.

Antiarrhythmic Drugs

Cardiac Arrhythmias 
Can originate in any part of the conduction system or from atrial or ventricular muscle.
Result from
– Disturbances in electrical impulse formation (automaticity) 
– Conduction (conductivity) 
– Both

MECHANISMS OF ARRHYTHMIA
ARRHYTHMIA – absence of rhythm
DYSRRHYTHMIA – abnormal rhythm

ARRHYTHMIAS result from:
1. Disturbance in Impulse Formation
2. Disturbance in Impulse Conduction
- Block results from severely depressed conduction
- Re-entry or circus movement / daughter impulse

Types of Arrhythmias

• Sinus arrhythmias 
– Usually significant only 
– if they are severe or  prolonged 

• Atrial arrhythmias 
– Most significant in the presence of underlying heart disease
– Serious: atrial fibrillation can lead to the formation of clots in the heart 

• Nodal arrhythmias 
– May involve tachycardia and increased workload of the heart or bradycardia from heart block 

• Ventricular arrhythmias 
– Include premature ventricular contractions (PVCs), ventricular tachycardia, and ventricular fibrillation 

Indications
• To convert atrial fibrillation (AF) or flutter to normal sinus rhythm (NSR) 
• To maintain NSR after conversion from AF or flutter 
• When the ventricular rate is so fast or irregular that cardiac output is impaired
– Decreased cardiac output leads to symptoms of decreased systemic, cerebral, and coronary circulation 
• When dangerous arrhythmias occur and may be fatal if not quickly terminated 
– For example: ventricular tachycardia may cause cardiac arrest 

Mechanism of Action 
• Reduce automaticity (spontaneous depolarization of myocardial cells, including ectopic pacemakers) 
• Slow conduction of electrical impulses through the heart
• Prolong the refractory period of myocardial cells (so they are less likely to be prematurely activated by adjacent cells 
 

Sufentanil

• A synthetic opioid related to fentanyl.
• About 7 times more potent than fentanyl.
• Has a slightly more rapid onset of action than fentanyl.

SULPHONAMIDES

Derivative of  sulphonilamide (Para-amino Benzene (PABA ) sulphonamide).

Anti-bacterial spectrum

Bacteriostatic to gram + and gram - bacteria. but bactericidal concentrations arce attained in urine. S pyogencs. H influenzae.E coli, few- Staph aureus. gonococci. pneumococci, proteus, shigella and Lymphogranuloma venereum.

Mechanism of action

Inhibits bacterial folate synthetase as they compete with PABA

Less soluble in acid urine and may precipitate to cause crystalluria.

Accumulate in patients with renal failure and can cause toxicity

Classification

Shart Acting (4-8 Hrs) sulphadiazine, sulphamethizole.

Intermediate acting(8-16 Hrs): sulphamethoxazole , sulphaphenazole

Long Acting(l-7days): sulphamethoxypyridazine.

Ultralong Acting(3-8days): sulfaline

Adverse effects

I. nausea, vomiting and epigastric pain

2. crystalluria

3. hypersensitivity-like polyarthritis nodosa. Steven-Johnson Syndrome. photosenstivity

4.hemolysis in G-6PD deficiency

5. kernicterus

They inhibit metabolism of phenytoin. tolbutamide. methotrexate

Therapeutic Use

UTI Meningitis, Streptococcal pharyngitis, Bacillary Dysentery

Hypothalamic - Pituitary Drugs

Somatropin

Growth hormone (GH) mimetic

Mechanism

agonist at GH receptors
increases production of insulin growth factor-1 (IGF-1)

Clinical use

GH deficiency
increase adult height for children with conditions associated with short stature 
Turner syndrome
wasting in HIV infection
short bowel syndrome

Toxicity

scoliosis
edema
gynecomastia
increased CYP450 activity

Octreotide

Somatostatin mimetic

Mechanism

agonist at somatostatin receptors

Clinical use

acromegaly
carcinoid
gastrinoma
glucagonoma
acute esophageal variceal bleed

Toxicity

GI upset
gallstones
bradycardia
Oxytocin

Mechanism

agonist at oxytocin receptor

Clinical use

stimulation of labor
uterine contractions
control of uterine hemorrhage after delivery
stimulate milk letdown

Toxicity

fetal distress 
abruptio placentae 
uterine rupture
Desmopressin
ADH (vasopressin) mimetic

Mechanism

agonist at vasopressin V2 receptors

Clinical use

central (pituitary) diabetes insipidus
hemophilia A (factor VIII deficiency)
increases availability of factor VIII
von Willebrand disease
increases release of von Willebrand factor from endothelial cells

Toxicity

GI upset
headache
hyponatremia
allergic reaction

Neomycin

used as a topical preparation

Neomycin is not absorbed from the gastrointestinal tract, and has been used as a preventative measure for hepatic encephalopathy and hypercholesterolemia. By killing bacteria in the intestinal tract, it keeps ammonia levels low and prevents hepatic encephalopathy, especially prior to GI surgery. It is not given intravenously, as neomycin is extremely nephrotoxic (it causes kidney damage), especially compared to other aminoglycosides.