Drug Interactions between cocaine nasal and Panadol Cold + Flu Non-Drowsy

GENERALLY AVOID: Concomitant use of cocaine with sympathomimetic agents such as epinephrine and phenylephrine may lead to additive cardiovascular effects. The proposed mechanism involves increased circulating catecholamines and increased activity of the sympathetic nervous system. Locally administered cocaine and epinephrine have been used in combination during septal surgery; however, concerns regarding cardiovascular side effects have been raised. Myocardial ischemia, myocardial infarction, and ventricular arrhythmias have been reported following coadministration of topical intranasal cocaine with epinephrine and phenylephrine during nasal and sinus surgery. Cases documenting the development of arrhythmias after the nasal application of cocaine and epinephrine 25%-0.18% topical paste have also been reported in 2 children and one adult receiving general anesthesia. However, the dosage of cocaine administered in these cases was above the maximum recommended dose in fit adults (1.5 mg/kg).

MANAGEMENT: Concomitant use of cocaine with sympathomimetic agents should be avoided. If coadministration is required, prolonged vital sign and ECG monitoring may be necessary.

MONITOR: Some topical anesthetics can be systemically absorbed and cause methemoglobinemia, particularly when applied to mucous membranes. Coadministration with other oxidizing agents that can also induce methemoglobinemia such as injectable local anesthetics, antimalarials (e.g., chloroquine, primaquine, quinine, tafenoquine), nitrates and nitrites, sulfonamides, aminosalicylic acid, dapsone, dimethyl sulfoxide, flutamide, metoclopramide, nitrofurantoin, phenazopyridine, phenobarbital, phenytoin, and rasburicase may increase the risk. Additional risk factors include very young age (e.g., infants less than 6 months); application to inflamed/abraded areas or broken skin; anemia; cardiac or pulmonary disease; peripheral vascular disease; liver cirrhosis; shock; sepsis; acidosis; and genetic predisposition (e.g., NADH cytochrome-b5 reductase deficiency; glucose-6-phosphate dehydrogenase (G6PD) deficiency; hemoglobin M). There have been rare reports of significant methemoglobinemia associated with administration of topical anesthetics, primarily following application to mucous membranes prior to dental procedures or via the oropharyngeal route prior to procedures such as intubation, laryngoscopy, bronchoscopy, and endoscopy. Very rarely, methemoglobinemia has also been reported with use of anesthetic throat lozenges.

MANAGEMENT: Caution is advised when topical anesthetics are used concomitantly with other methemoglobin-inducing agents. Clinicians should be aware of the potential for methemoglobinemia, particularly when topical anesthetics are applied to mucous membranes or given via the oropharyngeal route. Signs and symptoms of methemoglobinemia may be delayed some hours after drug exposure. Patients or their caregivers should be advised to seek medical attention if they notice signs and symptoms of methemoglobinemia such as slate-grey cyanosis in buccal mucous membranes, lips, and nail beds; nausea; headache; dizziness; lightheadedness; lethargy; fatigue; dyspnea; tachypnea; tachycardia; palpitation; anxiety; and confusion. In severe cases, patients may progress to central nervous system depression, stupor, seizures, acidosis, cardiac arrhythmias, syncope, shock, coma, and death. Methemoglobinemia should be considered if central cyanosis is unresponsive to oxygen. Calculated oxygen saturation and pulse oximetry are generally not accurate in the setting of methemoglobinemia. The diagnosis can be confirmed by an elevated methemoglobin level of at least 10% using co-oximetry. Methemoglobin concentrations greater than 10% of total hemoglobin will typically cause cyanosis, and levels over 70% are frequently fatal. However, symptom severity is not always related to methemoglobin levels. Experts suggest that treatment of methemoglobinemia varies from supplemental oxygen and symptom support to the administration of methylene blue, depending on severity of symptoms and/or the presence of G6PD deficiency. Institutional guidelines and/or individual product labeling should be consulted for further guidance.