Nystatin

Candida spp. are sensitive to nystatin.

Uses: Cutaneous, vaginal,  mucosal and  esophageal  infections.

Candida infections can be treated with nystatin.

Cryptococcus is also sensitive to nystatin.

Nystatin is often used as prophylaxis in patients who are at risk for fungal infections, such as AIDS patients with a low CD4+ count and patients receiving chemotherapy.

MOA

nystatin binds to ergosterol, the main component of the fungal cell membrane. When present in sufficient concentrations, it forms a pore in the membrane that leads to K+ leakage and death of the fungus.

Example calculations of maximum local anesthetic doses for a 15-kg child

Articaine

5 mg/kg maximum dose × 15 kg = 75 mg

4% articaine = 40 mg/mL

75 mg/(40 mg/mL) = 1.88 mL

1 cartridge = 1.8 mL

Therefore, 1 cartridge is the maximum

Lidocaine

7 mg/kg × 15 kg = 105 mg

2% lidocaine = 20 mg/mL

105 mg/(20 mg/mL) = 5.25 mL

1 cartridge = 1.8 mL

Therefore, 2.9 cartridges is the maximum

Mepivacaine

6.6 mg/kg × 15 kg = 99 mg

3% mepivacaine = 30 mg/mL

99 mg/(30 mg/mL) = 3.3 mL

1 cartridge = 1.8 mL

Therefore, 1.8 cartridges is the maximum.

Prilocaine

8 mg/kg × 15 kg = 120 mg

4% prilocaine = 40 mg/mL

120 mg/(40 mg/mL) = 3 mL

1 cartridge = 1.8 mL

Therefore, 1.67 cartridges is the maximum

Celecoxib

is a highly selective COX-2 inhibitor and primarily inhibits this isoform of cyclooxygenase, whereas traditional NSAIDs inhibit both COX-1 and COX-2. Celecoxib is approximately 10-20 times more selective for COX-2 inhibition over COX-1.

Being a sulphonamide can cause skin rash &  hypersensitivity rxn., occasional oedema& HT.

Indication

Osteoarthritis ( 100‐200mg BID ) , rheumatoid  arthritis, dysmenorrhea, acute gouty attacks,  acute musculoskeletal pain. 

Effects and Toxic Actions on Organ Systems

1. Local anesthetics (dose dependent) interfere with transmission in any excitable tissue (e.g. CNS and CVS).

2. CNS effects

 a. Central neurons very sensitive.

 b. Excitatory-dizziness, visual and auditory disturbances, apprehension, disorientation and muscle twitching more common with ester type agents.

 c. Depression manifested as slurred speech, drowsiness and unconsciousness more common with amide type agents (e.g. lidocaine).

 d. Higher concentrations of local anesthetic may eventually produce tonic-clonic[grand mal]  convulsions.

 e. Very large doses may produce respiratory depression which can be fatal. Artificial respiration may be life-saving.

 3.CVS effects

 a. Local anesthetics have direct action on the myocardium and peripheral vasculature by closing the sodium channel, thereby limiting the inward flux of sodium ions.

 b. Myocardium usually depressed both in rate and force of contraction. Depression of ectopic pacemakers useful in treating cardiac arrhythmias.

 c. Concentrations employed clinically usually cause vasodilation in area of injection.

 d. Vasoconstrictors such as epinephrine may counteract these effects on myocardium and vasculature.

4.  Local Tissue Responses

 a. Occasionally focal necrosis in skeletal muscle at injection site, decreased cell motility and delayed wound healing.

 b. Tissue hypoxia may be produced by action of excessive amounts of vasoconstrictors.

Needle selection

Nerve blocks:

Inferior alveolar- 25 G short (LLU technique)

PSA- 25 G short

Mental/Incisive- 25 G short

Palatal- 27/30 G short/ultrashort

Gow-Gates/Akinosi- 25 G long

Infraorbital- 25 G long

Field Block:

ASA 25/27 short

Infiltration:

Infiltration/SP 25/27 short

PDL/Intraosseous

PDL 27/30 short

Intraosseous 30 short/ultrashort

Cells of the Nervous System 

1-Neurons (Nerve Cells):function units of the nervous system by conducting nerve impulses, highly specialized and amitotic. Each has a cell body (soma), one or more dendrites, and a single axon. 
• Cell Body: it has a nucleus with at least one nucleolus and many of the typical cytoplasmic organelles, but lacks centriolesfor cell division. 

• Dendrites:Dendrites and axons are cytoplasmic extensions (or processes), that project from the cell body. They are sometimes referred to as fibers. Dendrites (afferent processes) increase their surface area to receive signals from other neurons, and transmit impulses to the neuron cell body. 

• Axon: There is only one axon (efferent process) that projects from each cell body.        
It carries impulses away from the cell body.

2-Glial cells: do not conduct nerve impulses, but support, nourish, and protect the neurons. They are mitotic, and far more numerous than neurons. 

Astrocyte: A glialcell that provides support for neurons of the CNS, provides nutrients regulates the chemical composition of the extracellularfluid.

• Oligodendrocyte: A type of glialcell in the CNS that forms myelin sheaths.

• Microglia:The smallest glialcells; act as phagocytes (cleaning up debris) and protect the brain from invading microorganisms.

• Schwann cell:A cell in the PNS that is wrapped around a myelinatedaxon, providing one segment of its myelin sheath.