Glice Special Precautions

Caution should be exercised in patients with severe liver or renal disease, hypothermia, hypothyroidism.
Glyceryl trinitrate should not be given by bolus injection.
Glyceryl trinitrate must be used only with particular caution and under medical supervision in: low filling pressures e.g., in acute myocardial infarction, impaired left ventricular function (left ventricular failure). Reducing systolic blood pressure below 90 mmHg must be avoided; orthostatic dysfunction.
The development of tolerance and cross tolerance to other nitro compounds has been described.
Glyceryl trinitrate must not be used in patients known to be taking phosphodiesterase inhibitor-containing products (e.g., sildenafil, vardenafil, tadalafil) in the intervening 24 hours (48 hours for tadalafil). Patients who receive glyceryl trinitrate solution therapy must be warned not to take phosphodiesterase inhibitor-containing products.
During treatment with glyceryl trinitrate, alcohol should be avoided as it may potentiate the hypotensive and vasodilating effect of glyceryl trinitrate.
Materials made of polyethylene (PE), polypropylene (PP), or polytetrafluoroethylene (PTFE) have proven to be suitable for infusing glyceryl trinitrate solution. However, infusion material made of polyvinyl chloride (PVC) or polyurethane (PU) has been shown to induce a loss of the active substance due to adsorption. If these materials are used the dose must be adjusted to suit patient's needs.
The solution contains glucose, this should be taken into account in patients with diabetes mellitus.
Hypoxemia: Caution should be exercised in patients with arterial hypoxemia due to severe anemia (including G6PD deficiency induced forms), because in such patients, the biotransformation of glyceryl trinitrate is reduced.
Similarly, caution is called for in patients with hypoxemia and ventilation/perfusion imbalance due to lung disease or ischemic heart failure.
Patients with angina pectoris, myocardial infarction, or cerebral ischemia frequently suffer from abnormalities of the small airways (especially alveolar hypoxia).
Under these circumstances vasoconstriction occurs within the lung to shift perfusion from areas of alveolar hypoxia to better ventilated region of the lung. As a potent vasodilator, glyceryl trinitrate could reverse this protective vasoconstriction and thus result in increased perfusion of poorly ventilated areas, worsening of the ventilation/perfusion imbalance, and a further decrease in the arterial partial pressure of oxygen.
Methemoglobinemia: Following treatment with glyceryl trinitrate, methemoglobinemia has been reported. Treatment of methemoglobinemia with methylene blue is contraindicated in patients with glucose-6-phosphate deficiency or methemoglobin-reductase deficiency.
Effects on ability to drive and use machines: Glyceryl trinitrate may affect the patient's reactivity to an extent that her/his ability to drive or to operate machinery is impaired. This effect is increased in combination with alcohol.