tetracaine (Tetcaine, tetracaine ophthalmic)
Dosing and uses of Tetcaine, tetracaine ophthalmic (tetracaine)
Adult dosage forms and strengths
injectable solution
- 0.2%
- 0.3%
- 1%
powder for injection
- 20mg
throat spray
- 2%
ophthalmic solution
- 0.5%
Spinal Anesthesia
High, median, low & saddle: 0.2%-0.3% solution
For perineum: 5 mg per dose
For lower extremities: 10 mg per dose
For saddle block: 2-5 mg per dose
Prolonged (2-3 hours): 1% solution
For spinal: 1% solution diluted 1:1 in CSF, administered at 1 mL per 5 seconds
Doses of >15 mg are rarely required, and should only be used in exceptional cases
Throat Spray
Apply to larynx, trachea, or esophagus (total dose no more than 20 mg)
Add epinephrine (0.06 mL of 0.1% solution to each mL) to retard absorption
Tetracaine/Epinephrine/Cocaine (TAC)
Currently LET is preferred to TAC
Tetracaine 0.5%, epinephrine 1:2000, cocaine 11.8%
Apply 2-5 mL x10-30 minutes
Onset:10-30 minutes after application
Duration: N/A
Ophthalmic
1-2 gtt [0.5% solution]
Other Indications & Uses
Epidural/caudal anesthesia; periph/sympathetic nerve block
Pediatric dosage forms and strengths
Safety & efficacy not established
Tetcaine, tetracaine ophthalmic (tetracaine) adverse (side) effects
Frequency not defined
Anxiety
Apprehension
Restlessness
Nervousness
Disorientation
Confusion
Dizziness
Blurred vision
Tremors
Twitching
Shivering
Seizures
CNS depression manifested by drowsiness, unconsciousness, respiratory arrest, nausea, vomiting, chills, miosis, tinnitus; myocardial depression, bradycardia, cardiac arrhythmias, hypotension, cardiovascular collapse, cardiac arrest; anxiety, palpitation, dizziness, headache, restlessness, tremors, tachycardia, anginal pain, hypertension (epinephrine-containing solutions)
Edema
Status asthmaticus
Anaphylactoid reactions (sometimes fatal)
Warnings
Contraindications
Hypersensitivity to aminobenzoic acid, sulfites, parabens, or any components of preparation
Cautions
Use preservative-free preparations for spinal or epidural anesthesia
Some formulations may contain sulfites
DO NOT use solutions with epinephrine in distal areas of body (eg, digit, nose, ear, etc)
Addition of vasoconstrictor, epinephrine, will promote local hemostasis, decrease systemic absorption, and increase duration of action
Do not use TAC on intact skin
Pregnancy and lactation
Pregnancy category: C
Lactation: not known if excreted in breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Tetcaine, tetracaine ophthalmic (tetracaine)
Duration: the greater the degree of vasodilation produced by the local anesthetic, the faster the rate of absorption and shorter the duration of action (bupivacaine has a long duration of action)
Protein Bound: highly
Metabolism: liver
Metabolites: ester- & amide-type local anesthetics
Excretion: urine (principally)
Mechanism of action
Local anesthetics prevent generation/conduction of nerve impulses by reducing sodium permeability & increasing action potential threshold
