As with any overdose, the first step is to assess the patient's airway, breathing, and circulation and to address these rapidly as needed. The cornerstone of treatment in benzodiazepine (BZD) overdoses is good supportive care and monitoring.
Single-dose activated charcoal is not routinely recommended, as the risks far outweigh the benefit. BZD are very rarely fatal in overdoses, and the altered mental status from BZD overdose greatly increases the risk of aspiration following oral charcoal dosing. 
Flumazenil (Romazicon) is a specific antidote for BZDs, but its use in acute BZD overdose is controversial and its risks usually outweigh any possible benefit.  In long-term BZD users, flumazenil may precipitate withdrawal and seizures; in patients taking BZDs for a medical condition, flumenazil may result in exacerbation of the condition.
Patients may be discharged if they remain asymptomatic at least 6 hours post ingestion. Those with mild toxicity may be observed in the emergency department until they recover. Patients with intentional overdoses require psychiatric evaluation before discharge. Admit patients with hemodynamic instability, coma, or respiratory depression to the intensive care unit (ICU). Respiratory depression may be treated with assisted ventilation.
Prehospital care for patients who have overdosed on benzodiazepines (BZDs) includes the following:
Supplemental oxygen and airway support
Intravenous (IV) access
Rapid glucose determination (finger stick) and administration of D50 if necessary
Naloxone can be administered at a very low dose (0.05 mg with a gradual increase if needed) if the diagnosis is unclear and an opioid co-ingestion is suspected (eg, if the patient has severe respiratory depression).
An important caveat is that although the administration of 0.4 mg of naloxone will reverse respiratory depression in most patients with opioid overdoses, it will also cause severe withdrawal symptoms (nausea, vomiting) in those who are opioid dependent. This can result in aspiration of gastric contents in patients who are unable to protect their airway because of sedation from the BZD.
Flumazenil is a competitive BZD receptor antagonist and is the only available specific antidote for BZDs. Its use in acute BZD is controversial, however, and its risks usually outweigh any benefit.  Common adverse events with flumazenil include agitation and gastrointestinal symptoms, while serious adverse events include supraventricular arrhythmia and convulsions. 
Flumazenil does not consistently reverse central respiratory depression due to BZDs, and over half the patients in a large multicenter study experienced re-sedation after use. 
In long-term BZD users, flumazenil may precipitate withdrawal and seizures; in patients taking BZDs for a medical condition, flumenazil may result in exacerbation of the condition.
In addition to those patients on long-term BZD use, flumazenil should not be used in any patient at an increased risk of having a seizure, including those with a seizure history, head injury, co-ingestion of BZD and tricyclic antidepressant or other proconvulsant, or even a possible ingestion of a proconvulsant. 
The ideal consideration for flumazenil use is for isolated iatrogenic BZD overdose in BZD-naive patients (eg, during conscious sedation of a BZD-naive patient).