Notwithstanding any other law, any minor who is at least twelve years of age who is found, upon diagnosis of a licensed physician or a registered nurse practitioner, to be under the influence of a dangerous drug or narcotic, which includes withdrawal symptoms, may be considered an emergency case and the minor is considered as having consented to hospital or medical care needed for treatment for that condition. Such consent is not subject to disaffirmance because of minority. The consent of the parent, parents or legal guardian of that minor is not necessary to authorize hospital or medical care, except that the consent is equally valid if obtained.