What special precautions should I follow?  

Before taking montelukast,

• tell your doctor and pharmacist if you are allergic to montelukast or any other medications.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention phenobarbital and rifampin (Rifadin, Rimactane). Your doctor may need to change the doses of your medications or monitor you more carefully for side effects.
• tell your doctor if you have or have ever had liver disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking montelukast, call your doctor.
• if you have phenylketonuria (PKU, a inherited condition in which a special diet must be followed to prevent mental retardation), you should know that the chewable tablets contain phenylalanine.

What special dietary instructions should I follow?  

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?