General
Considerable caution should be exercised in patients with hypertension, diabetes mellitus, ischemic heart disease, hyperthyroidism, increased intraocular pressure and prostatic hypertrophy. The elderly (60 years and older) are more likely to exhibit adverse reactions. Antihistamines may cause excitability, especially in children. At dosages higher than the recommended dose, nervousness, dizziness, or sleeplessness may occur.

Sympathomimetic amines should be used with caution in patients with hypertension, ischemic heart disease, diabetes mellitus increased intraocular pressure, hyperthyroidism or prostatic hypertrophy. Sympathomimetics may produce central nervous system stimulation with convulsions or cardiovascular collapse with accompanying hypotension.

Codeine Warning
Nursing infants whose mothers are taking codeine and are ultra-rapid metabolizers of codeine may be at increased risk for morphine overdose.

When physicians prescribe codeine-containing drugs to nursing women, they should inform their patients about the potential risks and the signs of morphine overdose. Nursing women taking codeine need to carefully watch their infants for signs of morphine overdose and seek medical attention immediately if the infant develops increased sleepiness (more than usual), difficulty breastfeeding or breathing, or decreased tone (limpness). Nursing mothers may also experience overdose symptoms such as extreme sleepiness, confusion, shallow breathing or severe constipation. When prescribing codeine to nursing mothers, physicians should choose the lowest effective dose for the shortest period of time and should closely monitor mother-infant pairs.

Drug metabolism is a complex process involving multiple genetic, environmental and physiologic factors. Limited evidence suggests that individuals who are ultra-rapid metabolizers (those with a specific CYP2D6 genotype) may convert codeine to its active metabolite, morphine, more rapidly and completely than other people. In nursing mothers, this metabolism can result in higher than expected serum and breast milk morphine levels. One published case report of an infant death raises concern that nursing babies may be at increased risk of morphine overdose if their mothers are taking codeine and are ultra-rapid metabolizers of the drug.

Usage in Ambulatory Patients
Dihydrocodeine may impair the mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery.

Respiratory Depression
Respiratory depression is the most dangerous acute reaction produced by opioid agonist preparations, although it is rarely severe with usual doses. Opioids decrease the respiratory rate, tidal volume, minute ventilation, and sensitivity to carbon dioxide. Respiratory depression occurs most frequently in elderly more debilitated patients, usually after large initial doses in non-tolerant patients, or when opioids are given in conjunction with other agents that depress respiration. This combination product should be used with caution in patients with significant chronic obstructive pulmonary disease or cor pulmonale and in patients with a substantially decreased respiratory r