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 or debilitated patients, usually after large initial doses in nontolerant 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 corpulmonale and in patients with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or respiratory depression. In such patients, alternative non-opioid analgesics should be considered, and opioids should be admin- istered only under careful medical supervision at the lowest effective dose.

Head Injury:
This combination product should be used cautiously in the presence of head injury or increased intracranial pressure. The effects of opioids on pupillary response and consciousness may obscure neurologic signs of increases in intracranial pressure in patients with head injuries. The respiratory depressant effects including carbon dioxide retention and secondary elevation of cerebrospinal fluid pressure may be markedly exaggerated in the presence of head injury, intracranial lesions, or other causes of increased intracranial pressures.

Hypotensive Effect:
Dihydrocodeine, like all opioid analgesics, may cause hypotension in patients whose ability to maintain blood pressure has been compromised by a depleted blood volume or who receive concurrent therapy with drugs such as phenothiazines or other agents which compromise vasomotor tone.

Acetaminophen, caffeine, and dihydrocodeine bitartrate tablets may produce orthostatic hypotension in ambulatory patients. This combination product should be administered with caution to patients in circulatory shock, since vasodilation produced by the drug may further reduce cardiac output and blood pressure.

Drug Dependence
Dihydrocodeine can produce drug dependence of the codeine type and has the potential of being abused (See DRUG ABUSE AND DEPENDENCE).

PRECAUTIONS:
General:
Selection of patients for treatment with Acetaminophen, caffeine, and dihydrocodeine bitartrate tablets should be governed by the same principles that apply to the use of similar opioid/non-opioid fixed combination analgesics. As with any such opioid analgesic, the dosing regimen should be adjusted for each patient (see DOSAGE AND ADMINISTRATION). This combination product should be used with caution in elderly or debilitated patients or those with any of the following conditions: acute alcoholism; adrenocortical insufficiency (e.g., Addison's disease); asthma; central nervous system depression or coma; chronic obstructive pulmonary disease; decreased respiratory reserve (including emphysema, severe obesity, cor pulmonale, or kyphoscoliosis); delirium tremens; head injury; hypotension; increased intracranial pressure; myxedema or hypothyroidism; prostatic hypertrophy or urethral stricture; and toxic psychosis. The benefits an