Singulair Cautions: Singulair (Montelukast) WILL NOT STOP AN ASTHMA ATTACK once one has started. IF YOU ARE ALSO USING A BRONCHODILATOR INHALER, be sure to always carry the inhaler with you to use during asthma attacks. Consult your doctor or pharmacist for specific advice on all drug therapy. CONTACT YOUR DOCTOR IF YOUR SYMPTOMS DO NOT IMPROVE or if they become worse while you are using this medicine. If your short-acting inhaler use increases or if use exceeds the 24-hour maximum prescribed by the doctor. DO NOT STOP Singulair (Montelukast) or any other asthma medicine without first checking with your doctor. KEEP ALL DOCTOR AND LABORATORY APPOINTMENTS while you are using this medicine. Laboratory and/or medical tests should be performed periodically to monitor your progress or check for side effects. Check with your doctor for more information. BEFORE YOU BEGIN TAKING ANY NEW MEDICINE, either prescription or over-the-counter, check with your doctor or pharmacist. PHENYLKETONURICS: this medicine may contain aspartame, if you have phenylketonuria (PKU) or any other condition where you must restrict your intake of aspartame (or phenylalanine), consult your doctor or pharmacist regarding the safe use of this medicine. FOR WOMEN: IF YOU PLAN ON BECOMING PREGNANT, discuss with your doctor the benefits and risks of using Singulair (Montelukast) during pregnancy. IT IS UNKNOWN IF Singulair (Montelukast) IS EXCRETED in breast milk. IF YOU ARE OR WILL BE BREAST-FEEDING while you are using Singulair (Montelukast), check with your doctor or pharmacist to discuss the risks to your baby.