Levobupivacaine (CHIROCAINE®) is a (S)-enantiomer of bupivacaine and it is related chemically and pharmacologically to the amino amide class of local anesthetics. Local anesthetics block the generation and the conduction of nerve impulses by increasing the threshold for electrical excitation in the nerve, by slowing propagation of the nerve impulse, and by reducing the rate of rise of the action potential. In general, the progression of anesthesia is related to the diameter, myelination, and conduction velocity of affected nerve fibers. Clinically, the order of loss of nerve function is as follows: 1) pain, 2) temperature, 3) touch, 4) proprioception and 5) skeletal muscle tone. Levobupivacaine (CHIROCAINE®) is a safer alternative for regional anesthesia than bupivacaine. It demonstrated less affinity and strength of depressant effects onto myocardial and central nervous vital centers in pharmacodynamic studies, and a superior pharmacokinetic profile.

Etidocaine, marketed under the trade name Duranest, is a local anesthetic given by injection during surgical procedures and labor and delivery. Etidocaine has a long duration of activity, and the main disadvantage of using during dentistry is increased bleeding during surgery. Etidocaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby effecting local anesthetic action.

Pyrrocaine is the amide local anesthetics. It is metabolized to 2,6-xylidine. It was used mainly as an infiltration and nerve block dental anesthetic in the 1960s and favored due to its rapid onset. The potency of pyrrocaine equals that of lidocaine in both sensory and motor nerve blocking. Pyrrocaine provided to be somewhat less toxic than lidocaine. No methemoglobinemia was clinically observed. It has been classified as unsafe for use in acute porphyria. There is no evidence that it is currently used commercially.

HYDROXYDIONE is a neuroactive steroid used formerly as a general anesthetic. It was discontinued due to a high incidence of post-anesthetic thrombophlebitis, delayed onset of anesthesia and an unacceptably long duration of action.

Thiamylal is a barbiturate that is administered intravenously for the production of complete anesthesia of short duration, for the induction of general anesthesia, or for inducing a hypnotic state. Thiamylal, a barbiturate, is used in combination with acetaminophen or aspirin and caffeine for its sedative and relaxant effects in the treatment of tension headaches, migraines, and pain. Barbiturates act as nonselective depressants of the central nervous system (CNS), capable of producing all levels of CNS mood alteration from excitation to mild sedation, hypnosis, and deep coma. In sufficiently high therapeutic doses, barbiturates induce anesthesia. Thiamylal binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Merethoxylline is a mercurial diuretic. As an equimolar mixture of merethoxylline procaine and theophylline in the molecular proportion 1:1.4 (DICURIN PROCAINE, Lilly) has been used in the treatment of oedema and ascites. The procaine component helps in reducing the discomfort of local irritation caused by mercurial compound when injected into tissues.