Meperidine (Demerol)

Meperidine is a phenylpiperidine and has a number of congeners. It is mostly effective in the CNS and bowel

• Produces analgesia, sedation, euphoria and respiratory depression.
• Less potent than morphine, 80-100 mg meperidine equals 10 mg morphine.
• Shorter duration of action than morphine (2-4 hrs).
• Meperidine has greater excitatory activity than does morphine and toxicity may lead to convulsions.
• Meperidine appears to have some atropine-like activity.
• Does not constrict the pupils to the same extent as morphine.
• Does not cause as much constipation as morphine.
• Spasmogenic effect on GI and biliary tract smooth muscle is less pronounced than that produced by morphine.
• Not an effective antitussive agent.
• In contrast to morphine, meperidine increases the force of oxytocin-induced contractions of the uterus.
• Often the drug of choice during delivery due to its lack of inhibitory effect on uterine contractions and its relatively short duration of action.
• It has serotonergic activity when combined with monoamine oxidase inhibitors, which can produce serotonin toxicity (clonus, hyperreflexia, hyperthermia, and agitation)

 Adverse reactions to Meperidine

• Generally resemble a combination of opiate and atropine-like effects.

- respiratory depression, - tremors, - delirium and possible convulsions, - dry mouth

• The presentation of mixed symptoms (stupor and convulsions) is quite common in addicts taking large doses of meperidine.

Meperidine (Demerol)

Meperidine is a phenylpiperidine and has a number of congeners. It is mostly effective in the CNS and bowel

• Produces analgesia, sedation, euphoria and respiratory depression.
• Less potent than morphine, 80-100 mg meperidine equals 10 mg morphine.
• Shorter duration of action than morphine (2-4 hrs).
• Meperidine has greater excitatory activity than does morphine and toxicity may lead to convulsions.
• Meperidine appears to have some atropine-like activity.
• Does not constrict the pupils to the same extent as morphine.
• Does not cause as much constipation as morphine.
• Spasmogenic effect on GI and biliary tract smooth muscle is less pronounced than that produced by morphine.
• Not an effective antitussive agent.
• In contrast to morphine, meperidine increases the force of oxytocin-induced contractions of the uterus.
• Often the drug of choice during delivery due to its lack of inhibitory effect on uterine contractions and its relatively short duration of action.
• It has serotonergic activity when combined with monoamine oxidase inhibitors, which can produce serotonin toxicity (clonus, hyperreflexia, hyperthermia, and agitation)

Dental implications of these drugs: 

1.    Adverse effects: gingival hyperplasia (phenytoin), osteomalacia (phenytoin, Phenobarbital), blood dyscrasias (all but rare)
2.    Drug interactions: additive CNS depression (anesthetics, anxiolytics, opioid analgesics), induction of hepatic microsomal enzymes (phenytoin, Phenobarbital, carbamazepine), plasma protein binding (phenytoin and valproic acid)
3.    Seizure susceptibility: stress can → seizures

Local Anesthetics

1. Procaine (Novocaine)

a) Classic Ester type agent, first synthetic injectable local anesthetic.

 b) Slow onset and short duration of action

 2. Tetracaine (Pontocaine)

a) Ester type agent--ten times as potent and toxic as procaine.

 b) Slow onset but long duration of action.

 c) Available in injectable and topical applications.

 3. Propoxycaine (Ravocaine)

a) Ester type agent–five times as potent and toxic as procaine.

 b) Often combined with procaine to increase duration of action.

 4. Lidocaine (Xylocaine)

a) Versatile widely used amide type agent.

 b) Two - three times as potent and toxic as procaine.

 c) Rapid onset and relatively long duration of action.

 d) Good agent for topical application.

 5. Mepivacaine (Carbocaine)

a) Amide type agent similar to lidocaine.

 b) Without vasoconstrictor has only short duration of action.

6. Prilocaine (Citanest)

a) Amide type agent — less potent than lidocaine.

 b) Without vasoconstrictor has only short duration of action.

 c) Metabolized to o-toluidine which can cause methemoglobinemia — significant only with large doses of prilocaine.

 d) Higher incidences of paresthesia reported with 4 % preparation

7. Bupivacaine (Marcaine)

a) Amide type agent of high potency and toxicity.

 b) Rapid onset and very long duration of action even without vasoconstrictor.

 8. Articaine (Septocaine)

a) Amide type agent

 b) Only amide-type local anesthetic that contains an ester group, therefore metabolized both in the liver and plasma.

 c) Approved by the FDA in 2000

 d) Evidence points to improved diffusion through hard and soft tissues as compared to other local anesthetics.

 e) Reports of a higher incidence of paresthesia, presumably due to the 4% concentration

 f) Not recommended for use in children under 4 years of age

Fourth Generation:

These are extended spectrum antibiotics. They are resistant to beta lactamases.

Cefipime

PLASMA FRACTIONS:

a) Fresh frozen plasma.

b) Platelets.

c) Plasma concentrates.

d) Non-plasma recombinant factor concentrates.