Interactions between Miochol Plus and Phenindamine

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Arrhythmia.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Asthma.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Asthma.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

Phenindamine has a moderate potential interaction with Cardiovascular Conditions and Disorders.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with COPD.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with COPD.

It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Corneal Abrasion.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Gastrointestinal Obstruction.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

Phenindamine has a moderate potential interaction with Glaucoma/Intraocular Hypertension.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Heart Attack.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Heart Failure.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with High Blood Pressure.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Hyperthyroidism.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Hypotension.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Hypotension.

Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Indigestion.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Irritable Bowel Syndrome.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Liver Disease.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Parkinsonism.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Peptic Ulcer.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Post MI Syndrome.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Renal Dysfunction.

Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Seizures.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Sinus Node Dysfunction.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.

Phenindamine has a moderate potential interaction with Urinary Retention.

Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.

The acetylcholine ophthalmic in Miochol Plus has a moderate potential interaction with Urinary Tract Obstruction.

Topically applied cholinergic agents are systemically absorbed, with the potential for producing rare but clinically significant systemic effects, including urinary incontinence, tightness of the bladder, increased gastric contractility and acid secretion, bradycardia, severe hypotension, bronchospasm, seizures, and coma. Increases in blood pressure may occur rarely due to a nicotinic effect on sympathetic ganglia. Therapy with ophthalmic cholinergic agents, particularly the long-acting cholinesterase inhibitors (e.g., demecarium and echothiophate), should be administered cautiously in patients with corneal abrasion (which may increase drug penetration), bronchospastic diseases, spastic gastrointestinal disturbances, urinary tract obstruction, peptic ulcer, pronounced bradycardia and hypotension, vascular hypertension, acute cardiac failure, recent myocardial infarction, epilepsy, parkinsonism, and other conditions that may respond adversely to vagotonic effects. The usual precautions should be followed to minimize the risk of systemic toxicity, including digital compression of the nasolacrimal ducts (1 to 2 minutes) following instillation to limit drainage into the nasal chamber, where extensive absorption may occur, and washing hands after use to prevent skin absorption. Excessive cholinergic effects may be reversed with parenterally administered atropine.