Propoxyphene

• A methadone analog.Used orally to relieve mild to moderate pain.
• A typical opiate, it does not possess anti-inflammatory or antipyretic actions, but has little or no antitussive activity.
• Cannot be used parenterally because of irritant properties.
• Has a low addiction potential primarily due to its lack of potency as an opiate.
• The most common adverse side effects are:• dizziness, drowsiness, and nausea and vomiting. • these effects are more prominent in ambulatory patients.
• Withdrawal symptoms have occurred in both adults and in neonates following use of the drug by the mother during pregnancy.
• CNS depression is additive with other CNS depressants.

TRIMETHOPRIM

It is a diaminopyrimidine. It inhibits bacterial dihydrofolate reductase( DHFRase).

In combination with sulphamethoxzole it is called Co-trimoxazole.

Spectrum of action

 S. Typhi. Serratia. Klebsiela and many sulphonamide resistant strains of Staph.aureus. Strep pyogens

Adverse effects

Megaloblastic anemia. i.e.. due to folate defeciency.

Contraindicated in pregnancy.

Diuretics if given with co-trimoxazole cause thrombocytopenia.

Uses

I. UTI. 2. RTI. 3. Typhoid. 5. Septicemias. 5. Whooping cough

Types of Neurons (Function)

•There are 3 general types of neurons (nerve cells): 

1-Sensory (Afferent ) neuron:A neuron that detects changes in the external or internal environment and sends information about these changes to the CNS. (e.g: rods and cones, touch receptors). They usually have long dendrites and relatively short axons. 

2-Motor (Efferent) neuron:A neuron located within the CNS that controls the contraction of    a muscle or the secretion of a gland. They usually have short dendrites and long axons. 

2-Interneuron or association neurons: A neuron located entirely within the CNS in which they form the connecting link between the afferent and efferent neurons. They have short dendrites and may have either a short or long axon.

Class III Potassium Channel Blockers

Prolong effective refractory period by prolonging Action Potential

Treatment: ventricular tachycardia and fibrillation, conversion of atrial fibrillation or flutter to  sinus rhythm, maintenance of sinus rhythm
– Amiodarone (Cordarone) – maintenance of sinus rhythm
– Bretylium (Bretylol) 
– Ibutilide (Corvert) 
– Dofetilide (Tykosyn) 
– Sotalol (Betapace) 

 Amiodarone 
- Has characteristics of sodium channel blockers, beta blockers, and calcium channel blockers 
- Has vasodilating effects and decreases systemic vascular resistance 
- Prolongs conduction in all cardiac tissue 
- Decreases heart rate 
- Decreases contractility of the left ventricles 

Class III - Adverse Effects 
- GI- Nausea vomiting and GI distress 
- CNS- Weakness and dizziness
- CV-Hypotension, CHF, and arrhythmias are common. 
- Amiodarone associated with potentially fatal Hepatic toxicity, ocular abnormalities and serious cardiac arrhythmias. 

Drug – Drug Interactions
These drugs can cause serious toxic effects if combined with digoxin or quinidine. 
 

Carbapenems: Broadest spectrum of beta-lactam antibiotics.

imipenem with cilastatin

meropenem

ertapenem

Monobactams: Unlike other beta-lactams, there is no fused ring attached to beta-lactam nucleus. Thus, there is less probability of cross-sensitivity reactions.

aztreonam

Beta-lactamase Inhibitors No antimicrobial activity. Their sole purpose is to prevent the inactivation of beta-lactam antibiotics by beta-lactamases, and as such, they are co-administered with beta-lactam antibiotics.

clavulanic acid

tazobactam

sulbactam

Patient positioning

The most common medical emergency encountered in the dental office setting is syncope. So patients in the supine or semi-supine position to improve venous return and cerebral blood flow provided that the position is tolerated by the patient and is appropriate for their medical condition.