Lidocaine adverse effects

Amide-type agents include articaine, lidocaine, bupivacaine, prilocaine, mepivacain and ropiva-caine. These are metabolized in the liver by microsomal enzymes with amidase activity. The amide group is preferred for parenteral and local use. If by accident rapidly administered intravascularly these agents, especially bupivacaine but also lidocaine, can produce serious and potentially lethal adverse effects including convulsions and cardiac arrest. They can more easily accumulate after multiple administrations. Intravenous lidocaine is sometimes used for regional anesthesia, for infiltration procedures, for the induction of nerve blockade and for epidural anesthesia. However, it is also used as an antiarrhythmic. Bupivacaine is a long-acting local anesthetic used for peripheral nerve blocks and epidural anesthesia. 

Lidocaine s most common adverse effects—like those of other local anesthetics—are neurologic paresthesias, tremor, nausea of central origin, lightheadedness, hearing disturbances, slurred speech, and convulsions. These occur most commonly in elderly or otherwise vulnerable patients or when a bolus of the drug is given too rapidly. The effects are dose-related and usually short-lived seizures respond to intravenous diazepam. In general, if plasma levels above 9 mcg/mL are avoided, lidocaine is well tolerated. 

The most important adverse effect of capsaicin is the initial burning sensation that it produces. Intravesical capsaicin induces intense suprapubic pain during intravesical instillation that may be made tolerable by lidocaine in some but not all patients. Capsaicin also frequently causes a transient worsening of the urinary conditions before improvement of symptoms due to desensitization of bladder afferents becoming evident. In patients with high spinal cord lesions capsaicin might provoke life-threatening autonomic dysreflexia. 

Adverse effects Lidocaine has a fairly wide toxic-to-therapeutic ratio it shows little impairment of left ventricular function, and has no negative inotropic effect. The CNS effects include drowsiness, slurred speech, paresthesia, agitation, confusion, and convulsions cardiac arrhythmias may also occur. 

ANAESTHETICS - LOCAL ANTIVIRALS-PROTEASE INHIBITORS t adverse effects of lidocaine with lopinavir and ritonavir Uncertain t bioavailability Caution consider using an alternative local anaesthetic... 

LIDOCAINE H2 RECEPTOR BLOCKERS -CIMETIDINE, RANITIDINE t efficacy and adverse effects of local anaesthetic, e.g. lightheadedness, paraesthesia Unknown for most local anaesthetics. Lidocaine t bioavailability Uncertain. Monitor more closely. No toxicity reported to date with bupiva-caine. If using intravenous lidocaine, monitor closely for symptoms of toxicity 1 dose may be required... 

Iontophoresis in the ear to relieve pain was reported by Albrecht in 1911 [47]. He used cocaine in high concentrations (20%-40%), copper electrodes, and uncontrolled high current (1.5-2 mA) on perforated tympanic membranes. Despite excellent anesthesia, many of his patients were vertiginous during and after treatment, with some patients suffering permanent loss of hearing. However, relatively recent studies have demonstrated that the use of lidocaine [48], A-acetylcysteine [49], or dexamethasone and fosfomycin [50] in iontophoresis to the ear has no adverse effects in either animal or clinical trials. Echols et al. [51] confirmed that lidocaine could be iontophoresed in the middle ear for at least 30 minutes at 1 mA without any adverse effects. 

Although an intermediate endpoint is associated with clinical benefit/ this benefit may be more than offset by the adverse effects of drug therapy when the ultimate outcome is considered. For example/ ventricular fibrillation is associated with increased mortality in the setting of acute myocardial infarction. The demonstration that lidocaine effectively prevents ventricular fibrillation in myocardial infarction patients at first provided a rationale for treating these patients prophylactically with this drug (7). However/ subsequent meta-analyses of several studies by MacMahon (8) and Hine (9) indicated that this use of lidocaine therapy actually worsens patient... 

The safety of articaine has been studied in a series of three randomized trials (2). The adverse effects deemed to be related to articaine were headache, paresthesia/ hyperesthesia after injection, infection, and rash. There was one case of mouth ulceration. The overall incidence of adverse effects was comparable to that of lidocaine. 

The use of a continuous epidural infusion of lidocaine 0.4% plus fentanyl 1 pg/ml in combination with intravenous metamizol 40 mg/kg provided significantly better analgesia than epidural morphine 20 pg/kg plus intravenous metamizol 40 mg/kg during the first 3 postoperative days in 30 children undergoing orthopedic surgery, without increasing the incidence of adverse effects however, the difference in beneficial effect was small (70). 

Local anesthetic gels and creams used liberally on traumatized epithehum can be rapidly absorbed, resulting in systemic effects, such as convulsions, particularly if excessive quantities are used. This has been highlighted in the case of a 40-year-old woman who developed seizures after hdocaine gel 40 ml was injected into the ureter during an attempt to remove a stone (1). Site of administration is also important, as local conditions, particularly vascularity, affect the rate of absorption. Adverse effects of lidocaine when it is used as a local anesthetic can also occur after inadvertent intravascular injection. 

Lidocaine has been used to treat some of the symptoms of multiple sclerosis in 30 patients with painful tonic seizures, attacks of neuralgia, paroxysmal itching, and Lhermitte s sign (8). Lidocaine was given by intravenous infusion for 5.5 hours in a maintenance dose of 2.0-2.8 mg/kg/hour after a loading dose, and the mean steady-state concentration was 2.4 pg/ml. Lidocaine almost completely abolished the paroxysmal symptoms and markedly alleviated the persistent symptoms of multiple sclerosis. Adverse effects were not specifically mentioned, but in one case, when the plasma concentration of lidocaine rose above 3.5 qg/ml, weakness of the left leg became marked and was associated with an extensor plantar response this disappeared when the lidocaine was replaced by saline single-blind, but subsequently the positive symptoms recurred. 

Intravenous lidocaine has been used to treat severe chronic daily headache in 19 patients (three men, median age 37 years) (9). There were adverse effects during four infusions of lidocaine hyperkalemia (6.4 mmol/1), which did not resolve after withdrawal of lidocaine transient hypotension (75/50 mmHg), which was attributed to concomitant droperidol an unspecified abnormality of cardiac rhythm and on another occasion a transient bradycardia and chest pain with a normal electrocardiogram, fever, and intractable nausea. The study was neither randomized nor placebo-controlled, and in no case was the adverse event strongly associated with the administration of lidocaine. 

In a double-blind, placebo-controUed study of the use of intravenous lidocaine for neuropathic pain, 16 patients were given 5 ml/kg intravenously over 30 minutes (10). Lidocaine was better than placebo in relieving pain. The major adverse effect was light-headedness, which occurred in seven patients given lidocaine and none given saline. Other adverse effects included somnolence, nausea and vomiting, dysarthria or garbled speech. 

Intranasal 4% lidocaine has been used for migraine and cluster headaches with success and few serious adverse effects a bitter taste was common and some patients complained of nasal burning and oropharyngeal numbness (SEDA-20,127). 

Lidocaine gel is not recommended for lubrication of laryngeal masks. It confers no benefits and increases the incidence of adverse effects such as intraoperative hiccups, postoperative hoarseness, nausea, vomiting, and tongue paresthesia (24). 

Topical 5% lidocaine to 33 patients with postherpetic neuralgia in a crossover trial provided significantly more pain relief than a vehicle patch placebo (41). There was no difference in reported adverse effects skin redness or rash was reported by 9 in the lidocaine patch phase and 11 in the placebo phase. One patient stopped using the placebo patch owing to red irritated skin, which resolved after the application of lidocaine patches. 

In a phase IV trial, 66% patients with postherpetic neuralgia gained relief from a 5% hdocaine patch applied to the most painful area of the body (43). The lidocaine patch was well tolerated, a rash being the most common adverse effect, in 14% of patients. 

The adverse effects of lidocaine are dose-related, and are more common in people of light weight and in patients with acute myocardial infarction or congestive cardiac failure. There is also an increased risk of central nervous system effects during cardiopulmonary bypass (60). In... 

The pharmacokinetics and safety of the 5% lidocaine patches have been studied in 20 healthy volunteers, who applied four patches to the skin either every 24 hours or every 12 hours for 3 days (67). Mean steady-state plasma concentrations were 186 and 225 ng/ml respectively, well below those required for an antidysrhythmic effect (1500 ng/ml) or a risk of toxicity (5000 ng/ml). The patches were well tolerated, with no major cutaneous adverse effects. This is in line with data from postmarketing surveillance studies, which have shown that since the availability of lidocaine patches in 1999, no adverse cardiac or other serious adverse events have been reported (68). 

Prilocaine 3% + felypressin 0.03 lU/ml has been compared with Udocaine 2% + adrenaline 12.5 micrograms/ml in 300 women having large-loop excision of the cervical transformation zone (289). Those who received lidocaine had significantly less blood loss, but were more likely to have adverse effects, including shaking and feeling faint. 

In 54 patients who received peribulbar anesthesia with either 1% ropivacaine or a mixture of 0.75% bupivacaine + 2% lidocaine there was no significant difference in akinesia scores or adverse effects reported the following day, notably headache, dizziness, nausea, scalp anesthesia, and diplopia, the latter occurring in 26% and 30% respectively (321). 

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