Because of the extensive vascular surface area in the lungs, blood-borne drugs expose the lungs to a risk for damage. Drug-induced pulmonary vascular diseases can lead to, and may clinically present with:
Pulmonary edema
- Interstitial (not within the alveolar sacs) lung disease
- Pulmonary vascular occlusion (blockage of a blood vessel)
- Pulmonary hypertension
- Pulmonary hemorrhage (discharge of bloody fluid from the endotracheal tube or upper respiratory tract)
- Pulmonary vasculitis (various disorders characterized by the destruction of blood vessels)
When these reactions are drug-related, it is important to recognize them as such because discontinuation of the offending drug along with supportive therapy often reverses them. Failure to identify pulmonary vascular disease and treat it as drug-related significantly increases subsequent morbidity and death.
Although the mechanics of how drugs cause pulmonary vascular damage is not well understood, there have been recent breakthroughs that have provided valuable insights. Due in part to studies of in vitro (in an artificial environment outside a living organism) and in vivo (within a living organism) acute lung injuries, an improved understanding has been gained in how drugs damage the lungs’ vascular bed by:
- Increasing microvascular hydrostatic pressure (pressure of the stationary fluid within the finer blood vessels in the lung)
- Increasing the permeability of the vascular endothelium (the layer of flat cells lining the inside of the blood vessels)
- Obstructing blood vessels and amplifying the resulting damage by activating inflammatory and immune mechanisms, stimulating intravascular coagulation, and/or inhibiting fibrinolysis (a process which keeps blood clots from growing)
- Impairing hemostasis (the stoppage of bleeding)
Drugs that have been associated with pulmonary vascular disease include:
- appetite suppressants (fenfluramine, dexfenfluramine, phentermine)
- busulfan (Myleran)
- methadone (Dolophine)
- methylphenidate (Concerta, Ritalin)
- nitrosoureas
Drugs associated with pulmonary vasculitis include:
- Sulfonamides
- Nitrofurantoin
- Penicillins
- Hydralazine hydrochloride
- Procainamide hydrochloride
- Foreign material injected intravenously (such as by drug abusers who may inject filler for capsules and tablets taken orally)
Causes of rhinitis include:
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Symptoms of rhinitis may include:
- Runny nose
- Nasal congestion
- Postnasal drip
- Coughing (due to postnasal drip)
- Sneezing
- Itchy nasal passages (especially when caused by allergies)
A diagnosis is based on the cause of the rhinitis and the duration of the symptoms.
Drug-induced rhinitis can be caused by various drugs, including:
- Estrogen supplements
- ACE inhibitors
- Beta-blockers
- Other antihypertensive drugs
- Antidepressants
- Antianxiety drugs
- Aspirin
- Decongestant nasal sprays (can lead to rebound nasal decongestion when used for more than three days at a time)
Treatment for drug-induced rhinitis involves discontinuation of the offending drug. Corticosteroid nasal sprays may sometimes be used to help ease the symptoms while the body rids itself of the causal agent. Withdrawal from long-term regular use of a nasal decongestion spray may need to be referred to an ear, nose, and throat specialist.