| Paclitaxel | Oncology | LC/MS/MS | 50-10000 ng/mL | Dog Plasma |
| Paclitaxel | Oncology | LC/MS/MS | 5-5000 ng/mL | Human Sodium Heparinized Plasma |
| Paclitaxel | Oncology | LC/MS/MS | 5-2500 ng/mL | K2-EDTA human plasma |
| Pantoprazole | Gastrointestinal | LC/MS/MS | 20-4000 ng/mL | Human Lithium Heparinized Plasma |
| Pantoprazole | Gastrointestinal | HPLC/UV | 20-2000 ng/mL | Human EDTA Plasma |
| Pantoprazole | Gastrointestinal | LC/MS/MS | 20-4000 ng/mL | Human EDTA Plasma |
| Paricalcitol | Rheumatology | LC/MS/MS | 10-1000 pg/mL | Human EDTA Plasma |
| Paroxetine | Central Nervous System Agents | LC/MS/MS | 0.25-50 ng/mL | Human EDTA Plasma |
| Paroxetine | Central Nervous System Agents | LC/MS/MS | 100-15000 pg/mL | Human EDTA Plasma |
| Paroxetine | Central Nervous System Agents | LC/MS/MS | 0.1-30 ng/mL | Human K3 EDTA Plasma |
| Pegasys (Pegylated Interferon alpha 2a) | Respiratory | Elisa | 312.5-40000 pg/mL | Human Serum |
| Pemetrexed | Oncology | LC/MS/MS | 1-200 µg/mL | Human EDTA Plasma |
| Penciclovir | Infectious Disease | LC/MS/MS | 50-10000 ng/mL | Human EDTA Plasma |
| Pentazocine | Pain | LC/MS/MS | 5-800 ng/mL | Human Plasma |
| Pentoxifylline; Metabolite I; Metabolite V | Hematologic Agent | LC/MS/MS | 1-500 ng/mL; 2-1000 ng/mL; 3-1500 ng/mL | Human EDTA Plasma |
| Pentoxyfilline | Genitourinary | HPLC/UV | 10-400 ng/mL | Human Plasma |
| Pergolide | Central Nervous System Agents | LC/MS/MS | 2-50 pg/mL | Human EDTA Plasma |
| Perindopril; Perindoprilat | Cardiovascular | LC/MS/MS | 400-160000 pg/mL ; 100-40000 pg/mL | Human EDTA Plasma |
| Phenylbutazone | Pain | HPLC/UV | 0.1-50 µg/mL | Horse Plasma |
| Phenylephrine | Respiratory | LC/MS/MS | 2-400ng/mL | Monkey EDTA K2 Plasma |
| Phenylephrine free | Infectious Disease | LC/MS/MS | 10-2500 pg/mL | Human Plasma |
| Phenytoin | Central Nervous System Agents | LC/MS/MS | 25-2500 ng/mL | Human Plasma |
| Pinaverium | Gastrointestinal | LC/MS/MS | 5-2500 pg/mL | Human EDTA Plasma |
| Pioglitazone; Hydroxypioglitazone | Endocrinology | LC/MS/MS | 10-3000 ng/mL; 10-1500 ng/mL | Human EDTA Plasma |
| Pioglitazone; Hydroxypioglitazone; Ketopioglitazone | Endocrinology | LC/MS/MS | 10-2000 ng/mL; 20-2000 ng/mL; 4-800 ng/mL | Human EDTA Plasma |
| Piracetam | Central Nervous System Agents | LC/MS/MS | 0.5-5 µg/mL | Human EDTA plasma |
| Piretanide | Cardiovascular | LC/MS/MS | 0.5-300 ng/mL | Human EDTA Plasma |
| Pirlindole | Central Nervous System Agents | LC/MS/MS | 0.5-500 ng/mL | Human Plasma |
| Platinum (Free) | Oncology | ICP-MS | 5-1000ng/mL | Human EDTA K3 Plasma |
| Platinum (Total) | Oncology | ICP-MS | 5-1000ng/mL | Human EDTA K3 Plasma |
| Posaconazole | TBD | LC/MS/MS | 1-500 ng/mL | Human EDTA Plasma |
| Potassium | Miscellaneous | ICP-MS | 200-40000µg/mL | Human Urine |
| Pramipexole | Central Nervous System Agents | LC/MS/MS | 50-5000 pg/ml | Human EDTA Plasma |
| Pramipexole | Central Nervous System Agents | LC/MS/MS | 10.01-1004 pg/mL | Human EDTA Plasma |
| Pravastatin | Cardiovascular | LC/MS/MS | 0.4-200 ng/mL | Human EDTA Plasma |
| Pravastatin; 3-a-hydroxy Pravastatin | Cardiovascular | LC/MS/MS | 0.25-100 ng/mL; 0.25-50ng/mL | Human EDTA Plasma |
| Pravastatin; 3-a-hydroxy Pravastatin | Cardiovascular | LC/MS/MS | 0.25-100 ng/mL ; 0.25-50 ng/mL | Human Lithium Heparinized Plasma |
| Prednisolone | Ophtalmic | LC/MS/MS | 1-500ng/mL | Human ETDA K3 Plasma |
| Prednisolone | Ophtalmic | LC/MS/MS | 1-100 ng/mL | Rat Plasma |
| Prednisone; Prednisolone | Immunology | LC/MS/MS | 1-50 ng/mL; 5-250 ng/mL | Rabbit K3 EDTA Plasma |
| Prednisone; Prednisolone | Immunology | LC-MS/MS | 1-50 ng/ml; 5-250 ng/ml | Human EDTA Plasma |
| Pregabalin | Central Nervous System Agents | LC/MS/MS | 30.07-15036 ng/mL | Human EDTA Plasma |
| Primidone | Central Nervous System Agents | LC/MS/MS | 20-2000 ng/mL | Human EDTA Plasma |
| Progesterone | Endocrinology | RIA | 100-40000 pg/mL | Human Serum |
| Progesterone | Endocrinology | LC/MS/MS | 100-50000 pg/mL | Human EDTA Plasma |
| Promethazine | Respiratory, Gastrointestinal | LC/MS/MS | 0.5-20 ng/mL | Human EDTA Plasma |
| Propanolol Total; 4-Hydroxypropanolol | Cardiovascular | LC/MS/MS | 0.5-100 ng/mL | Human EDTA Plasma |
| Propofol | Central Nervous System Agents | LC/MS | 5-3000 ng/mL | Human Whole Blood |
| Propranolol Total | Cardiovascular | LC/MS/MS | 1-400 ng/mL | Human EDTA Plasma |
| Propranolol Total; 4-hydroxypropranolol | Cardiovascular | LC/MS/MS | 2-400 ng/mL; 0.5-100 ng/mL | Human EDTA Plasma |
| Propylene glycol | Miscellaneous | LC/MS/MS | 1-500 ug/mL | Human Plasma |
| Pseudoephedrine | Respiratory | LC/MS/MS | 6-600 ng/mL | Human EDTA Plasma |
| Pseudoephedrine | Respiratory | LC/MS/MS | 0.2-100 ng/mL | Human Plasma |
| Pseudoephedrine | Respiratory | LC/MS | 5-500 ng/mL | Human EDTA Plasma |
| Pyridoxal | Miscellaneous | LC/MS/MS | 10-400 ng/mL | Human Whole Blood |
| Pyridoxal-5-Phosphate | Miscellaneous | LC/MS/MS | 2-100 ng/mL | Human Plasma |
| Pyridoxamine | Miscellaneous | LC/MS/MS | 200-50000 pg/mL | Human Blood |
| Pyridoxamine | Miscellaneous | LC/MS/MS | 200-50000 pg/mL | Human Plasma |
| Pyridoxamine 5-phosphate | Miscellaneous | LC/MS/MS | 500-50000 pg/mL | Human Blood |
| Pyridoxine | Miscellaneous | LC/MS/MS | 1-200 ng/mL | Human Plasma |