tetracaine (Pantocaine)

Introduction

Tradename: Pontocaine. (tetracaine hydrochloride) Ophthalmic agent:

Indications

• local anesthesia of the eye for:
  • diagnostic procedures
  • foreign body or suture removal
  • paracentesis of the anterior chamber
  • short-term procedures involving the cornea or conjunctiva
• spinal anesthesia
• topical anethesia applied to the nose & throat for various diagnostic procedures
• pruritus, superficial injury, skin irritation

Contraindications

• ophthlamic: secondary bacterial infection

Dosage

• 1-2 drops into the eye prior to procedure
• spinal anesthesia: 5-20 mg of 1% solution into subarachnoid space
• saddle block: 2-5 mg of a 1% solution dilute with an equal volume of CSF before administration
• topical to mucous membrane: apply 2% solution as needed; total dose should not exceed 20 mg

Injection: 1% (2 mL) Ointment (ophthalmic): 0.5% (3.75 g) Solution (ophthalmic): 0.5% (1 mL), 0.2%, 0.3%, 1%

Pharmacokinetics

• anesthesia within 25-60 seconds (ophthalmic) or within 3 minutes topical to mucous membranes or spinal anesthesia
• duration of action: up to 15 minutes; 1.5-3 hours
• metabolized by the liver & plasma
• metabolites are excreted in the urine

elimination via liver

elimination via plasma

elimination via kidney

Adverse effects

• not common (1-10%)
  • contact dermatitis, burning, stinging, angioedema
• uncommon (< 1%)
  • methemoglobinemia in infants, tenderness, urticaria, edema, urethritis
• prolonged use has been associated with:
  • severe keratitis
  • corneal opacification

Mechanism of action

• blocks both the initiation & conduction of nerve impulses

More general terms

• local anesthetic

Component of

• oxymetazoline/tetracaine
• mineral oil/tetracaine
• benzocaine/lidocaine/tetracaine
• lidocaine/tetracaine (Synera)
• benzocaine/tetracaine
• benzocaine/benzalkonium chloride/butyl aminobenzoate/tetracaine (Cetacaine)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5411
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=8695
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=57749