Drugs Used in Diabetes

Goals of diabetes treatment

lower serum glucose to physiologic range
keep insulin levels in physiologic range
eliminate insulin resistance

best initial step in management: weight loss, contractile-based exercise weight loss is more important for insulin sensitivity than is a low-carb diet

Modalities of diabetes treatment

Type I DM

insulin
low-sugar diet

Type II DM
exercise
diet
insulin

6 classes of drugs 

Insulin
Sulfonylureas -    Glyburide
Meglitinides  - Nateglinide
Biguanides    Metformin    
Glitazones (thiazolidinediones)    Pioglitazone
α-glucosidase inhibitors    Acarbose
GLP-1 mimetics (incretin mimetics)    Exenatide
Amylin analog    Pramlintide

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.

CLASSICATION OF ANTICOAGULANT DRUGS

1. Direct Acting Anticoagulants

a) Calcium Chelators (sodium citrate, EDTA)

b) Heparin

2. Indirect Acting Anticoagulant Drugs

a) Warfarin

FUNDAMENTALS OF INJECTION TECHNIQUE

There are 6 basic techniques for achieving local anesthesia of the structures of the oral cavity:

 1. Nerve block

 2. Field block

 3. Infiltration/Supraperiosteal

 4. Topical

 5. Periodontal ligament (PDL)

 6. Intraosseous

 Nerve block- Nerve block anesthesia requires local anesthetic to be deposited in close proximity to a nerve trunk. This results in the blockade of nerve impulses distal to this point. It is also important to note that arteries and veins accompany these nerves and can be damaged. To be effective, the local anesthetic needs to pass only through the nerve membrane to block nerve conduction Field block/Infiltration/Supraperiosteal - Field block, infiltration and supraperiosteal injection techniques, rely on the ability of local anesthetics to diffuse through numerous structures to reach the nerve or nerves to be anesthetized:

  - Periosteum

 - Cortical bone

 - Cancellous bone

 - Nerve membrane

Topical - Topical anesthetic to be effective requires diffusion through mucous membranes and nerve membrane of the nerve endings near the tissue surface

PDL/Intraosseous - The PDL and intraosseous injection techniques require diffusion of local anesthetic solution through the cancellous bone (spongy) to reach the dental plexus of nerves innervating the tooth or teeth in the immediate area of the injection. The local anesthetic then diffuses through the nerve membrane

Etomidate  -Intravenous Anesthetics

- A nonbarbiturate anesthetic used primarily to induce surgical anesthesia.
- It does not produce analgesia.
- Etomidate has minimal effect on the cardiovascular system and respiration during induction of anesthesia.
- Like the barbiturates, etomidate decreases cerebral blood flow, cerebral metabolic rate and intracranial pressure.
- No changes in hepatic, renal or hematologic function have been reported.
- Myoclonic muscle movements are relatively common.
- Postoperative nausea and vomiting are more common with etomidate than with barbiturates.

Thiazide diuretics

Chlorothiazide, Hydrochlorothiazide

Mechanism(s) of Action

1.    Block facilitated Na/Cl co-transport in the early distal tubule. This is a relatively minor Na absorption mechanism and the result is modest diuresis 

2.    Potassium wasting effect 

a.    Blood volume reduction leads to increased production of aldosterone 
b.    Increased distal Na load secondary to diuretic effect 
c.    a + b = increase Na (to blood) for K (to urine) exchange which produces indirect K wasting

3.    Increase distal Ca re-absorption (direct effect) 

o    causes an increase in plasma calcium.This is unimportant NORMALLY but makes thiazides VERY inappropriate choice for hypercalcemic patients.

4.    Anti-diuretic effect in nephrogenic diabetes insipidus patients secondary to depletion of Na and Water. 

Toxicity
 
•    Electrolyte imbalance (particularly hypokalemia) ,Agranulocytosis , Allergic reactions 
•    Hyperuricemia , Thrombocytopenia