Initially, 1 to mg/kg IV. If ventricular fibrillation or pulseless ventricular tachycardia persist, additional to mg/kg IV doses can be given every 5 to 10 minutes up to a total loading dose of 3 mg/kg. The same dose may be given via the intraosseous route when IV access is not available. There is inadequate evidence to support the routine use of lidocaine after cardiac arrest; however, the initiation or continuation of lidocaine may be considered after return of spontaneous circulation (ROSC) from cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia. If a maintenance lidocaine infusion is warranted for an individual patient, administer 1 to 4 mg/minute (30 to 50 mcg/kg/minute) IV. Use lower infusion rates for patients who are elderly, have heart failure or hepatic disease, or are debilitated. Lidocaine is considered an alternative antiarrhythmic to amiodarone for this indication, particularly when amiodarone is not available. Lidocaine is convenient to administer but is not as effective as amiodarone for improving ROSC or survival to hospital admission among adult patients with VF refractory to a shock and epinephrine. Neither drug has been shown to improve survival to hospital discharge in cardiac arrest patients with VF.
The origin of the name tretinoin is uncertain,   although several sources agree (one with probability,  one with asserted certainty  ) that it probably comes from trans- + retinoic [acid] + -in , which is plausible given that tretinoin is the all-trans isomer of retinoic acid . The name isotretinoin is the same root tretinoin plus the prefix iso- . Regarding pronunciation, the following variants apply equally to both tretinoin and isotretinoin . Given that retinoic is pronounced / ˌ r ɛ t ɪ ˈ n oʊ ɪ k / ,     it is natural that / ˌ t r ɛ t ɪ ˈ n oʊ ɪ n / is a commonly heard pronunciation. Dictionary transcriptions also include / ˌ t r ɪ ˈ t ɪ n oʊ ɪ n / ( tri- TIN -oh-in )   and / ˈ t r ɛ t ɪ n ɔɪ n / .