Ester-type drugs Procaine:Procaine: The only indication for its use in dentistry is in patients with proven allergy to the amide group.The only indication for its use in dentistry is in patients with proven allergy to the amide group. Used intra-arterially, as part of the recognized regimen, to treat the arteriospasm which might occur during intravenous sedation.Used intra-arterially, as part of the recognized regimen, to treat the arteriospasm which might occur during intravenous sedation. It has an excellent vasodilatory properties.It has an excellent vasodilatory properties.

Ester-type drugs Procaine (cont) Onset & duration of Action:Onset & duration of Action: Has a very shot duration (5 minutes) and a long onset time of 10 minutesHas a very shot duration (5 minutes) and a long onset time of 10 minutes Dosages:Dosages: The maximum dose is 6 mg/kg, 400 mg max.The maximum dose is 6 mg/kg, 400 mg max. Used as 2% with 1: epinephrine to increase efficacy.Used as 2% with 1: epinephrine to increase efficacy. Metabolism:Metabolism: Rapidly by plasma esterase.Rapidly by plasma esterase.

Ester-type drugs Benzocaine:Benzocaine: Used mainly as topical, due to its poor water solubility, and because of its low toxicity, it is used in concentration up to 20%.Used mainly as topical, due to its poor water solubility, and because of its low toxicity, it is used in concentration up to 20%. Hydrolyzed rapidly by plasma esterase to p-aminobenzoic acid accounting for its low toxicity.Hydrolyzed rapidly by plasma esterase to p-aminobenzoic acid accounting for its low toxicity.

Ester-type drugs Cocaine:Cocaine: The first and most potent local anaesthetic agent, rarely used because of the problems of misuse.The first and most potent local anaesthetic agent, rarely used because of the problems of misuse. It is unique in it is ability to produce intense vasoconstriction. Half life 30 minutes.It is unique in it is ability to produce intense vasoconstriction. Half life 30 minutes. Dosage:Dosage: Used as topical 4 – 10% solutionUsed as topical 4 – 10% solution Maximum dose is 1.5 mg/kg – 100mg max.Maximum dose is 1.5 mg/kg – 100mg max. Used intranasally during apical surgery.Used intranasally during apical surgery.

Amide-type drugs: Lignocaine (Lidocaine):Lignocaine (Lidocaine): Synthesized in 1943 and used in dentistry since 1948 and is also known as XylocaineSynthesized in 1943 and used in dentistry since 1948 and is also known as Xylocaine It highly lipophilic (partition coefficient 3), rapidly absorbed.It highly lipophilic (partition coefficient 3), rapidly absorbed. Metabolized only in the liver and its metabolites are less toxic with no action.Metabolized only in the liver and its metabolites are less toxic with no action. Has half-life ( t 0.5 ) of 90 minutesHas half-life ( t 0.5 ) of 90 minutes

Amide-type drugs Lignocaine (cont) Dosage:Dosage: 4.4 mg/kg – 300 mg max4.4 mg/kg – 300 mg max Used as 2% plain or with 1: epinephrineUsed as 2% plain or with 1: epinephrine 4 and 10% spray, 2% gel and 5% ointments.4 and 10% spray, 2% gel and 5% ointments. Onset & duration of action:Onset & duration of action: Rapid onset 2 – 3 minutesRapid onset 2 – 3 minutes Plain- short duration (10 minutes)Plain- short duration (10 minutes) With epinephrine- intermediate duration (45 – 60 minutes)With epinephrine- intermediate duration (45 – 60 minutes)

Amide-type drugs Prilocaine:Prilocaine: A very potent local anaesthetic and is less toxic than Lignocaine.A very potent local anaesthetic and is less toxic than Lignocaine. It produces less vasodilatation than lignocaineIt produces less vasodilatation than lignocaine Rate of clearance is higher than other amide-types, suggesting extra-hepatic metabolism with relatively low blood concentration.Rate of clearance is higher than other amide-types, suggesting extra-hepatic metabolism with relatively low blood concentration. It’s metabolite o-toluidine lead to methaemo- globinaemia (more than 600 mg in adults)It’s metabolite o-toluidine lead to methaemo- globinaemia (more than 600 mg in adults)

Amide-type drugs Prilocaine Used either plain 4% or 3% combined with 0.03IU/mL of Felypressin as vasoconstrictor.Used either plain 4% or 3% combined with 0.03IU/mL of Felypressin as vasoconstrictor. Onset & Duration:Onset & Duration: Slower onset – 4 minutes.Slower onset – 4 minutes. It’s duration of action is similar to Lignocaine.It’s duration of action is similar to Lignocaine. Dosage;Dosage; 6.0 mg/kg – max. 400 mg.6.0 mg/kg – max. 400 mg. Combined with Lignocaine as a topical anaesthetic agent to be used prior to vene-section and during dental sedation in children.Combined with Lignocaine as a topical anaesthetic agent to be used prior to vene-section and during dental sedation in children.

Amide-type drugs Mepivacaine:Mepivacaine: Possess the least vasodilating effect.Possess the least vasodilating effect. Metabolized in the liver and has t 0.5 of 120 minutes.Metabolized in the liver and has t 0.5 of 120 minutes. It’s main indication is when local anaesthetic without vasoconstrictor is needed. 3% plain is more effective than lignocaine.It’s main indication is when local anaesthetic without vasoconstrictor is needed. 3% plain is more effective than lignocaine. Onset & duration:Onset & duration: Rapid onset but slightly shorter duration.Rapid onset but slightly shorter duration.

Amide-type drugs Bupivacaine:Bupivacaine: A long-acting local anaesthetic agent, with a t 0.5 of 160 minutes due grater binding capacity to plasma protein and tissue proteinsA long-acting local anaesthetic agent, with a t 0.5 of 160 minutes due grater binding capacity to plasma protein and tissue proteins Metabolized in the liver.Metabolized in the liver. Used mainly in Oral surgical procedures for its long- lasting pain control.Used mainly in Oral surgical procedures for its long- lasting pain control. Longer onset and longer duration (Regional 6 – 8 hors)Longer onset and longer duration (Regional 6 – 8 hors) Dosage:Dosage: 1.3 mg/kg – Max 90 mg1.3 mg/kg – Max 90 mg 0.25 – 0.75% with or without adrenaline 1: – 0.75% with or without adrenaline 1:

Amide-type drugs Etidocaine:Etidocaine: A long-acting agent similar to Bupivacaine but with faster onset.A long-acting agent similar to Bupivacaine but with faster onset. Metabolized in the liver.Metabolized in the liver. Dosage:Dosage: 8 mg/kg – Max 400 mg8 mg/kg – Max 400 mg 1.5% with 1: epinephrine.1.5% with 1: epinephrine. Lignocaine is the most common used agent both topically and by injection as 2% with or without adrenaline, with a maximum dose of 4.4 mg/kg.Lignocaine is the most common used agent both topically and by injection as 2% with or without adrenaline, with a maximum dose of 4.4 mg/kg.

Vasoconstrictors Originally added to reduce systemic uptake in an attempt to limit toxicity.Originally added to reduce systemic uptake in an attempt to limit toxicity. Prolong the durationProlong the duration Produces profound anaesthesia.Produces profound anaesthesia. Reduce operative bleeding.Reduce operative bleeding. Two types:Two types: Sympathomimetic naturally occurring.Sympathomimetic naturally occurring. Synthetic polypeptides, FelypressinSynthetic polypeptides, Felypressin

Vasoconstrictors Epinephrine: (Adrenaline)Epinephrine: (Adrenaline) Uses in dentistry:Uses in dentistry: Local anaesthetic solution.Local anaesthetic solution. Gingival retraction cords.Gingival retraction cords. In the ER as life-saving drug in anaphylaxis.In the ER as life-saving drug in anaphylaxis. Mechanism of action:Mechanism of action: Interact with adrenergic receptors in the vesselsInteract with adrenergic receptors in the vessels α 1 & α 2 producing vasoconstriction in skin & MMα 1 & α 2 producing vasoconstriction in skin & MM β 2 stimulation causing vasodilatation in skeletal muscles.β 2 stimulation causing vasodilatation in skeletal muscles.

Vasoconstrictors Epinephrine Metabolism:Metabolism: Appears very rapidly in the systemic circulation !!!Appears very rapidly in the systemic circulation !!! Exogenously administered epinephrine is metabolized extraneuronal and 1% is excreted in the urine unchanged.Exogenously administered epinephrine is metabolized extraneuronal and 1% is excreted in the urine unchanged. Dosage:Dosage: 1:80,000 is the commonest dose used, 12.5 µ g/ml1:80,000 is the commonest dose used, 12.5 µ g/ml

Vasoconstrictors Epinephrine Systemic effect:Systemic effect: Being a naturally occurring hormone, it exert a number of physiological responses on the different systems.Being a naturally occurring hormone, it exert a number of physiological responses on the different systems. The heart:The heart: Has direct and indirect action.Has direct and indirect action. Direct action on β 1 receptors increases the rate and force of contraction raising cardiac output.Direct action on β 1 receptors increases the rate and force of contraction raising cardiac output. Indirect action, increase pulse and cardiac output, lead to rise in systolic blood pressure, (not with dental dose)Indirect action, increase pulse and cardiac output, lead to rise in systolic blood pressure, (not with dental dose)

Vasoconstrictors Epinephrine Blood vessels:Blood vessels: Contain α 1, α 2 and β 2 adrenoreceptors in the vessels of the skin, mucous membrane and skeletal muscles.Contain α 1, α 2 and β 2 adrenoreceptors in the vessels of the skin, mucous membrane and skeletal muscles. Action on α 1 receptors causes vasoconstriction since they are susceptible to endogenous nor-epinephrine and exogenous epinephrine. Reduce operative bleedingAction on α 1 receptors causes vasoconstriction since they are susceptible to endogenous nor-epinephrine and exogenous epinephrine. Reduce operative bleeding α 2 receptors are only susceptible to circulating epinephrine.α 2 receptors are only susceptible to circulating epinephrine.

Vasoconstrictors Epinephrine β 2 found in the skeletal muscles, and very uncommon in the skin and mucous membrane. β 2 stimulation result in vasodilatation, lowering peripheral resistance and a fall in the diastolic blood pressure. (with dental dose)β 2 found in the skeletal muscles, and very uncommon in the skin and mucous membrane. β 2 stimulation result in vasodilatation, lowering peripheral resistance and a fall in the diastolic blood pressure. (with dental dose) Haemostasis:Haemostasis: The vasoconstricting effect.The vasoconstricting effect. Adrenaline promote platelets aggregation in the early stages.Adrenaline promote platelets aggregation in the early stages. Fibrinolytic activity compromise clot stability.Fibrinolytic activity compromise clot stability.

Vasoconstrictors Epinephrine Lungs:Lungs: Stimulation of β 2 receptors in the lung lead to bronchial muscle relaxation, life-saving in bronchial (spasm) constriction during anaphylactic reaction.Stimulation of β 2 receptors in the lung lead to bronchial muscle relaxation, life-saving in bronchial (spasm) constriction during anaphylactic reaction. Wound healing:Wound healing: Reduced local tissue oxygen tension.Reduced local tissue oxygen tension. Epinephrine-induced fibrinolysis.Epinephrine-induced fibrinolysis.

Vasoconstrictors Felypressin:Felypressin: It is an analogue of the naturally occurring Vasopressin.It is an analogue of the naturally occurring Vasopressin. Bind to vasopressin V 1 receptor in the vascular smooth muscle producing vaso-constriction and reduce local blood flow.Bind to vasopressin V 1 receptor in the vascular smooth muscle producing vaso-constriction and reduce local blood flow. Less potent than the catecholamines &poorer control of bleeding during operative procedures.Less potent than the catecholamines &poorer control of bleeding during operative procedures. Acts on the venous side rather than the arterial side.Acts on the venous side rather than the arterial side. Dose:Dose: 0.03 IU/ml (0.54 µ g/ml)0.03 IU/ml (0.54 µ g/ml)

Local anaesthesia Complications & Unwanted effects:Complications & Unwanted effects: Psychogenic effects:Psychogenic effects: Fainting and is not related to the drugsFainting and is not related to the drugs Reduce incidence by the use of sympathetic management and the semi-supine position during injection.Reduce incidence by the use of sympathetic management and the semi-supine position during injection. Infection:Infection: HIV and Hepatitis.HIV and Hepatitis. Appropriate cross-infection control measures should be employed to reduce the risk.Appropriate cross-infection control measures should be employed to reduce the risk.

Local anaesthesia Hypersensitivity:Hypersensitivity: Drug allergy to local anaesthesia is very rare.Drug allergy to local anaesthesia is very rare. Ranges from localized reaction to type-I anaphylaxis.Ranges from localized reaction to type-I anaphylaxis. Mainly due to the ester-type agents compared to amide-type.Mainly due to the ester-type agents compared to amide-type. Preservative, Methylparaben, found in local anaesthetic solutions may be a more likely cause allergy rather than the local anaesthetic.Preservative, Methylparaben, found in local anaesthetic solutions may be a more likely cause allergy rather than the local anaesthetic. Paraben-free amide local anaesthetic agents are now available.Paraben-free amide local anaesthetic agents are now available.

Local anaesthesia Hypersensitivity: Clinically:Clinically: Start with flushing and itching of the mucous membrane.Start with flushing and itching of the mucous membrane. Followed by sever difficulty in breathing due to laryngospasm and bronchospasm.Followed by sever difficulty in breathing due to laryngospasm and bronchospasm. Then sever drop in blood pressure with rapid, weak and almost imperceptible pulse.Then sever drop in blood pressure with rapid, weak and almost imperceptible pulse. The condition progress rapidly and mostly fatal.The condition progress rapidly and mostly fatal. The earlier the onset of symptoms following the drug, the most sever and dangerous the reaction.The earlier the onset of symptoms following the drug, the most sever and dangerous the reaction.

Local anaesthesia Hypersensitivity: Treatment:Treatment: Immediate.Immediate. Patient is placed horizontal on the dental chair or on the floor.Patient is placed horizontal on the dental chair or on the floor. Oxygen administered or mouth-to-mouth respiration.Oxygen administered or mouth-to-mouth respiration. 0.5 ml of 1:1000 (0.1 mg/ml) epinephrine I.M.0.5 ml of 1:1000 (0.1 mg/ml) epinephrine I.M. Followed byFollowed by