DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed advanced solid tumor that is not curable by conventional therapy
• Brain metastases allowed if adequately controlled with radiotherapy

PATIENT CHARACTERISTICS:

Age:

• Over 18

Performance status:

• Karnofsky 60-100%

Life expectancy:

• At least 12 weeks

Hematopoietic:

• WBC at least 3,500/mm^3
• Absolute neutrophil count at least 2,000/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• SGOT and SGPT no greater than 3 times normal
• Bilirubin no greater than 2.0 mg/dL

Renal:

• Creatinine no greater than 1.5 mg/dL
• Creatinine clearance greater than 60 mL/min
• BUN no greater than 25 mg/dL

Cardiovascular:

• Adequate cardiovascular function
• No congestive heart failure (New York Heart Association class III or IV heart disease)
• No angina pectoris AND/OR
• No significant arrhythmia
• No myocardial infarction within the past 6 months
• No clinically significant ischemic cardiac disease currently under treatment
• No clinically significant conduction system disease in the absence of a pacemaker (e.g., sick sinus syndrome, or second or third degree atrioventricular block)

Pulmonary:

• Adequate pulmonary function
• No clinical evidence of acute chronic obstructive pulmonary disease
• FEV1 at least 50% predicted
• Arterial oxygen tension at least 90% by pulse oximetry and on breathing room air
• No asthma OR
• No evidence of more than 20% reversibility in FEV1 with albuterol therapy

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No history of severe adverse reaction to adenosine
• No uncontrolled medical illness
• No average daily pain scores of at least 5 on a simple Visual Analogue Self pain assessment (0-10) scale

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics
• At least 3 weeks since prior radiotherapy and recovered

Surgery:

• Not specified

Other:

• At least 30 days since prior investigational therapy
• At least 14 days since prior long-term theophylline, dipyridamole, or dipyridamole/aspirin therapy
• No concurrent long-term theophylline, dipyridamole, or dipyridamole/aspirin therapy
• No concurrent maintenance anti-anginal drug therapy