2023

• Materstvedt, Lars Johan; Fredheim, Olav Magnus Søndenå. (2023) Lindrende sedering er avansert helsehjelp til døende. Dagens medisin.
  Feature article

2022

• Werff, Hans Fredrik Leendert van der; Michelet, Torstein Hagen; Fredheim, Olav Magnus; Steine, Siri. (2022) “Do not resuscitate” order and end-of-life treatment in a cohort of deceased in a Norwegian University Hospital. Acta Anaesthesiologica Scandinavica. volum 66 (8).
  Academic article

2021

• Fredheim, Olav Magnus; Materstvedt, Lars Johan; Skulberg, Ingeborg M; Magelssen, Morten. (2021) Ought the level of sedation to be reduced during deep palliative sedation? A clinical and ethical analysis. BMJ Supportive & Palliative Care.
  Academic article
• Fredheim, Olav Magnus; Skurtveit, Svetlana Ondrasova; Sjøgren, Per; Aljabri, Mohammad Belal; Hjellvik, Vidar. (2021) Prescriptions of analgesics during chronic cancer disease trajectories: A complete national cohort study. Pharmacoepidemiology and Drug Safety. volum 30 (11).
  Academic article
• Hamina, Aleksi; Handal, Marte; Fredheim, Olav; Clausen, Thomas; Chen, Li-Chia; Skurtveit, Svetlana Ondrasova. (2021) Filled prescriptions for opioids among children and adolescents – A nationwide study from 2010 to 2018. Acta Anaesthesiologica Scandinavica. volum 65 (10).
  Academic article
• Holmberg, Siril Therese; Fredheim, Olav Magnus; Skurtveit, Svetlana Ondrasova; Salvesen, Øyvind; Nygaard, Øystein Petter; Gulati, Agnete Malm; Solberg, Tore; Gulati, Sasha. (2021) Persistent Use of Prescription Opioids Following Lumbar Spine Surgery: Observational Study with Prospectively Collected Data from Two Norwegian Nationwide Registries. Spine. volum 47 (8).
  Academic article

2020

• Fredheim, Olav Magnus; Skulberg, Ingeborg M; Magelssen, Morten; Steine, Siri. (2020) Clinical and ethical aspects of palliative sedation with propofol—A retrospective quantitative and qualitative study. Acta Anaesthesiologica Scandinavica.
  Academic article
• Fredheim, Olav Magnus; Skurtveit, Svetlana; Loge, Jon Håvard; Sjøgren, Per; Handal, Marte; Hjellvik, Vidar. (2020) Prescription of analgesics to long-term survivors of cancer in early adulthood, adolescence and childhood in Norway: a national cohort study. Pain. volum 161 (5).
  Academic article
• Gustad, Kristine Espengren; Askjer, Åsta; Nortvedt, Per; Fredheim, Olav Magnus; Magelssen, Morten. (2020) Refractory suffering at the end of life and the assisted dying debate: An interview study with palliative care nurses and doctors. Clinical Ethics.
  Academic article
• Holmberg, Siril Therese; Salvesen, Øyvind; Vangen-Lønne, Vetle; Hara, Sozaburo; Fredheim, Olav Magnus; Solberg, Tore; Jakola, Asgeir S; Solheim, Ole; Nygaard, Øystein Petter; Gulati, Sasha. (2020) Pain During Sex Before and After Surgery for Lumbar Disc Herniation - A Multicenter Observational Study. Spine.
  Academic article

2019

• Birke, Hanne; Ekholm, Ola; Sjøgren, Per; Fredheim, Olav Magnus; Clausen, Thomas; Skurtveit, Svetlana. (2019) Tramadol use in Norway: A register-based population study. Pharmacoepidemiology and Drug Safety. volum 28 (1).
  Academic article
• Fredheim, Olav Magnus; Kaasa, Stein; Borchgrevink, Petter Chr.. (2019) Smertebehandling ved kronisk kreftsykdom. Tidsskrift for Den norske legeforening. volum 139 (13).
  Feature article
• Fredheim, Olav Magnus; Magelssen, Morten. (2019) Etiske dilemmaer ved suicidalitet hos pasienter med kort forventet levetid. Tidsskrift for Den norske legeforening. volum 139 (16).
  Academic article
• Fredheim, Olav Magnus; Skurtveit, Svetlana; Handal, Marte; Hjellvik, Vidar. (2019) A complete national cohort study of prescriptions of analgesics and benzodiazepines to cancer survivors in Norway 10 years after diagnosis. Pain. volum 160 (4).
  Academic article

2018

• Fredheim, Olav Magnus. (2018) Smertebehandling hos kreftpasienter i legemiddelassistert rehabilitering. Tidsskrift for Den norske legeforening. volum 138 (2).
  Article
• Nøstdal, Torkjell; Bernklev, Tomm; Fredheim, Olav Magnus; Paddison, Johanna S.; Ræder, Johan. (2018) Defining the cut-off point of clinically significant postoperative fatigue in three common fatigue scales. Quality of Life Research.
  Academic article

2017

• Fredheim, Olav Magnus Søndenå; Brelin, Siri; Hjermstad, Marianne Jensen; Loge, Jon Håvard; Aass, Nina Kathrine; Johannessen, Tom Børge; Skurtveit, Svetlana. (2017) Prescriptions of analgesics during complete disease trajectories in patients who are diagnosed with and die from cancer within the five-year period 2005-2009. European Journal of Pain. volum 21 (3).
  Academic article
• Fredheim, Olav Magnus; Skurtveit, Svetlana; Borchgrevink, Petter Chr.. (2017) Utlevering av analgetika til barn f?r og etter nye anbefalinger om kodein. Tidsskrift for Den norske legeforening. volum 137 (12).
  Academic article
• Nøstdal, Torkjell; Fredheim, Olav Magnus; Bernklev, Tomm; Doksrød, Tron Simen; Mohus, Randi Marie; Ræder, Johan. (2017) A randomised controlled trial of propofol vs. thiopentone and desflurane for fatigue after laparoscopic cholecystectomy. Anaesthesia. volum 72 (7).
  Academic article

2016

• Brelin, Siri; Fredheim, Olav Magnus; Loge, Jon Håvard; Skurtveit, Svetlana; Johannesen, Tom Børge; Aass, Nina Kathrine; Ottesen, Stig; Hjermstad, Marianne Jensen. (2016) Opioids for outpatients with cancer in their last year of life: A nationwide pharmacoepidemiological study. Journal of Opioid Management. volum 12 (1).
  Academic article
• Fredheim, Olav Magnus; Hansen, Thor Willy Ruud; Haugen, Guttorm; Magelssen, Morten. (2016) Bør man kunne tilby keisersnitt ved trisomi 13 og 18?. Tidsskrift for Den norske legeforening. volum 136 (7).
  Academic article
• Fredheim, Olav Magnus; Hansen, Thor Willy Ruud; Haugen, Guttorm; Magelssen, Morten. (2016) O. Fredheim og medarbeidere svarer. Tidsskrift for Den norske legeforening. volum 136 (10).
  Letter to the editor
• Fredheim, Olav Magnus; Hansen, Thor Willy Ruud; Haugen, Guttorm; Magelssen, Morten. (2016) O. Fredheim og medarbeidere svarer :. Tidsskrift for Den norske legeforening. volum 136 (11).
  Reader opinion piece
• Fredheim, Olav Magnus; Hansen, Thor Willy Ruud; Haugen, Guttorm; Magelssen, Morten. (2016) Re: Keisersnitt ved trisomi 13 og 18 - en verdibasert vurdering :. Tidsskrift for Den norske legeforening. volum 136 (14/15).
  Reader opinion piece
• Hansen, AB; Borchgrevink, Petter Chr.; Skurtveit, S; Romundstad, Pål Richard; Fredheim, Olav Magnus. (2016) Consumption of and satisfaction with health care among opioid users with chronic non-malignant pain. Acta Anaesthesiologica Scandinavica. volum 60 (2).
  Letter to the editor
• Mellbye, Andreas; Borchgrevink, Petter Chr.; Skurtveit, Svetlana; Fredheim, Olav Magnus. (2016) Hva vet vi om bruken av opioider ved ikke-malign smerte? : resultater fra studier basert på Reseptregisteret 2004-2014. Norsk Farmaceutisk Tidsskrift. volum 124 (3).
  Academic literature review
• Mellbye, Andreas; Karlstad, Øystein; Skurtveit, Svetlana; Borchgrevink, Petter Chr.; Fredheim, Olav Magnus. (2016) The duration and course of opioid therapy in patients with chronic non-malignant pain. Acta Anaesthesiologica Scandinavica. volum 60 (1).
  Academic article
• Nøstdal, Torkjell; Bernklev, Tomm; Ræder, Johan; Sandvik, Leiv; Fredheim, Olav Magnus. (2016) Postoperative fatigue translation and validation of a revised 10-item short form of the Identity-Consequence Fatigue Scale (ICFS). Journal of Psychosomatic Research. volum 84.
  Academic article

2015

• Dale, Ola; Borchgrevink, Petter Chr.; Fredheim, Olav Magnus; Mahic, Milada; Romundstad, Pål Richard; Skurtveit, Svetlana. (2015) Prevalence of use of non-prescription analgesics in the Norwegian HUNT3 population: Impact of gender, age, exercise and prescription of opioids. BMC Public Health. volum 15.
  Academic article
• Fredheim, Olav Magnus; Mahic, Milada; Skurtveit, Svetlana; Borchgrevink, Petter Chr.. (2015) Use of nasal fentanyl for cancer pain: A pharmacoepidemiological study. Palliative Medicine. volum 29 (7).
  Academic article
• Hansen, Anneli Borge; Skurtveit, Svetlana; Borchgrevink, Petter Chr.; Dale, Ola; Romundstad, Pål Richard; Mahic, Milada; Fredheim, Olav Magnus. (2015) Consumption of and satisfaction with health care among opioid users with chronic non-malignant pain. Acta Anaesthesiologica Scandinavica. volum 59 (10).
  Academic article
• Pedersen, Line; Fredheim, Olav Magnus. (2015) Opioids for chronic noncancer pain: Still no evidence for superiority of sustained-release opioids. Clinical Pharmacology and Therapeutics. volum 97 (2).
  Academic literature review

2014

• Fredheim, Olav Magnus; Mahic, Milada; Skurtveit, Svetlana; Dale, Ola; Romundstad, Pål Richard; Borchgrevink, Petter Chr.. (2014) Chronic pain and use of opioids: A population-based pharmacoepidemiological study from the Norwegian Prescription Database and the Nord-Trøndelag Health Study. Pain. volum 155 (7).
  Academic article
• Mahic, Milada; Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Skurtveit, Svetlana. (2014) Use of prescribed opioids by children and adolescents: Differences between Denmark, Norway and Sweden. European Journal of Pain. volum 19 (8).
  Academic article
• Mellbye, Andreas; Karlstad, Øystein; Skurtveit, Svetlana; Borchgrevink, Petter Chr.; Fredheim, Olav Magnus. (2014) Co-morbidity in persistent opioid users with chronic non-malignant pain in Norway. European Journal of Pain. volum 18 (8).
  Academic article
• Pedersen, Line; Borchgrevink, Petter Chr.; Breivik, Harald; Fredheim, Olav Magnus. (2014) A randomized, double-blind, double-dummy comparison of short- and long-acting dihydrocodeine in chronic non-malignant pain. Pain. volum 155 (5).
  Academic article
• Pedersen, Line; Borchgrevink, Petter Chr.; Riphagen, Ingrid Ingeborg; Fredheim, Olav Magnus. (2014) Long- or short-acting opioids for chronic non-malignant pain? A qualitative systematic review. Acta Anaesthesiologica Scandinavica. volum 58 (4).
  Academic article
• Svendsen, Kristian; Fredheim, Olav Magnus; Romundstad, Pål Richard; Borchgrevink, Petter Chr.; Skurtveit, Svetlana. (2014) Persistent opioid use and socio-economic factors: A population-based study in Norway. Acta Anaesthesiologica Scandinavica. volum 58 (4).
  Academic article

2013

• Fredheim, Olav; Borchgrevink, Petter; Mahic, Milada; Skurtveit, Svetlana. (2013) A pharmacoepidemiological cohort study of subjects starting strong opioids for nonmalignant pain: A study from the Norwegian Prescription Database. Pain. volum 154 (11).
  Academic article
• Skollerud, Lars Morten; Fredheim, Olav Magnus; Svendsen, Kristian; Skurtveit, Svetlana; Borchgrevink, Petter Chr.. (2013) Laxative prescriptions to cancer outpatients receiving opioids: a study from the Norwegian prescription database. Supportive Care in Cancer. volum 21 (1).
  Academic article

2012

• Fredheim, Olav Magnus; Husby, Kristin Moksnes; Borchgrevink, Petter Chr.; Skurtveit, Svetlana. (2012) Opioid switching to methadone: A pharmacoepidemiological study from a national prescription database. Palliative Medicine. volum 26 (6).
  Academic article
• Fredheim, Olav Magnus; Materstvedt, Lars Johan. (2012) Behandlingsbegrensning på operasjonsstuen?. Tidsskrift for Den norske legeforening.
  Academic article
• Mellbye, Andreas; Svendsen, Kristian; Borchgrevink, Petter Chr.; Skurtveit, Svetlana; Fredheim, Olav Magnus. (2012) Concomitant medication among persistent opioid users with chronic non-malignant pain. Acta Anaesthesiologica Scandinavica. volum 56 (10).
  Academic article
• Nordbø, Arve; Skurtveit, Svetlana; Borchgrevink, Petter Chr.; Kaasa, Stein; Fredheim, Olav Magnus. (2012) Low-dose transdermal buprenorphine - long-term use and co-medication with other potentially addictive drugs. Acta Anaesthesiologica Scandinavica. volum 56 (1).
  Academic article
• Pedersen, Line; Hansen, Anneli Borge; Svendsen, Kristian; Skurtveit, Svetlana; Borchgrevink, Petter Chr.; Fredheim, Olav Magnus. (2012) Analgetika med refusjon ved kroniske smerter. Tidsskrift for Den norske legeforening. volum 132 (22).
  Academic literature review
• Rognstad, May Karin; Fredheim, Olav Magnus; Johannessen, Tone E.Brenne; Kvarstein, Gunnvald; Skauge, Marta; Undall, Eva; Rustøen, Tone. (2012) Attitudes, beliefs and self-reported competence about postoperative pain among physicians and nurses working on surgical wards. Scandinavian Journal of Caring Sciences. volum 26 (3).
  Academic article
• Svendsen, Kristian; Skurtveit, Svetlana; Romundstad, Pål Richard; Borchgrevink, Petter Chr.; Fredheim, Olav Magnus. (2012) Differential patterns of opioid use: Defining persistent opioid use in a prescription database. European Journal of Pain. volum 16 (3).
  Academic article

2011

• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.. (2011) Dødshjelp er ikke livshjelp. Vårt land.
  Reader opinion piece
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Kvarstein, Gunnvald. (2011) Behandling av postoperativ smerte i sykehus. Tidsskrift for Den norske legeforening. volum 131 (18).
  Academic literature review
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Nordstrand, Berit; Clausen, Thomas; Skurtveit, Svetlana. (2011) Prescription of analgesics to patients in opioid maintenance therapy: A pharmacoepidemiological study. Drug and Alcohol Dependence. volum 116 (1-3).
  Academic article
• Fredheim, Olav Magnus; Kvarstein, Gunnvald; Undall, Eva; Stubhaug, Audun; Rustøen, Tone; Borchgrevink, Petter Chr.. (2011) Postoperativ smerte hos pasienter innlagt i norske sykehus. Tidsskrift for Den norske legeforening. volum 18 (131).
  Academic article
• Fredheim, Olav Magnus; Magelssen, Morten. (2011) Hvorfor reservasjonsrett for helsepersonell?. Stavanger Aftenblad.
  Feature article
• Magelssen, Morten; Fredheim, Olav Magnus. (2011) En åndelig dimensjon er viktig for mange pasienter. Tidsskrift for Den norske legeforening. volum 131 (2).
  Feature article
• Magelssen, Morten; Fredheim, Olav Magnus. (2011) Når bør leger ha reservasjonsrett?. Tidsskrift for Den norske legeforening. volum 131 (24).
  Feature article
• Skurtveit, Svetlana; Furu, Kari; Borchgrevink, Petter Chr.; Handal, Marte; Fredheim, Olav Magnus. (2011) To what extent does a cohort of new users of weak opioids develop persistent or probable problematic opioid use?. Pain. volum 152 (7).
  Academic article
• Skurtveit, Svetlana; Furu, Kari; Handal, Marte; Borchgrevin, Petter; Fredheim, Olav Magnus. (2011) To Which Extent Does a Cohort of New Users of Weak Opioids Develop Persistent or Probable Problematic Opioid Use?. Pharmacoepidemiology and Drug Safety. volum 20.
  Abstract
• Svendsen, Kristian; Borchgrevink, Petter Chr.; Fredheim, Olav Magnus; Hamunen, K; Melbye, Arne Christian; Dale, Ola. (2011) Choosing the unit of measurement counts: The use of oral morphine equivalents in studies of opioid consumption is a useful addition to defined daily doses. Palliative Medicine. volum 25 (7).
  Academic article

2010

• Fredheim, Olav Magnus. (2010) Muskelfysiologi og kronisk smerte. Tidsskrift for Den norske legeforening. volum 130 (22).
  Book review
• Fredheim, Olav Magnus. (2010) Sjekklister – ikke bare for nevrotikere. Tidsskrift for Den norske legeforening. volum 130 (21).
  Book review
• Fredheim, Olav Magnus S; Log, Tomas; Olsen, Wenche; Skurtveit, Svetlana; Sagen, Øystein; Borchgrevink, Petter C. (2010) Prescriptions of opioids to children and adolescents; a study from a national prescription database in Norway. Pediatric Anaesthesia. volum 20 (6).
  Academic article
• Fredheim, Olav Magnus S; Skurtveit, Svetlana; Breivik, Harald; Borchgrevink, Petter C. (2010) Increasing use of opioids from 2004 to 2007-Pharmacoepidemiological data from a complete national prescription database in Norway. European Journal of Pain. volum 14 (3).
  Academic article
• Fredheim, Olav Magnus; Dale, Ola; Kaasa, Stein; Borchgrevink, Petter Chr.. (2010) Morfin eller oksykodon tabletter mot smerter?. Tidsskrift for Den norske legeforening. volum 130 (15).
  Academic article
• Fredheim, Olav Magnus; Nøstdahl, Torkjell; Nordstrand, Berit; Høivik, Tone Gulli; Rygnestad, Tarjei; Borchgrevink, Petter Chr.. (2010) Behandling av akutte smerter under legemiddelassistert rehabilitering. Tidsskrift for Den norske legeforening. volum 130 (7).
  Academic article
• Fredheim, Olav Magnus; Skurtveit, Svetlana; Breivik, Harald; Svendsen, Kristian; Kaasa, Stein; Borchgrevink, Petter Chr.. (2010) A revision of EAPC and WHO three step analgesic ladder may be needed. Palliative Medicine. volum 24 (4).
  Abstract
• Fredheim, Olav Magnus; Skurtveit, Svetlana; Breivik, Harald; Svendsen, Kristian; Kaasa, Stein; Borchgrevink, Petter Chr.. (2010) Cancer patients acount for only 3% of patients receiving opioids in Norway. Palliative Medicine. volum 24 (4).
  Abstract
• Magelssen, Morten; Fredheim, Olav Magnus. (2010) Det bestes fiende. Vårt land.
  Feature article

2009

• Borchgrevink, Petter Chr.; Fredheim, Olav Magnus; Fors, Egil Andreas; Holen, Are; Stiles, Tore C. (2009) Hva er sammensatte lidelser?. Tidsskrift for Den norske legeforening. volum 129 (13).
  Short communication
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Breivik, Harald. (2009) Olav Magnus S. Fredheim og medarbeidere svarer. Tidsskrift for Den norske legeforening. volum 129.
  Letter to the editor
• Fredheim, Olav Magnus; Breivik, Harald; Ødegaard, Raida. (2009) Lengevirkende versus langtidsvirkende. Tidsskrift for Den norske legeforening. volum 129.
  Short communication
• Fredheim, OM; Skurtveit, Svetlana; Moroz, A; Breivik, H; Borchgrevink, PC. (2009) Prescription pattern of codeine for non-malignant pain: a pharmacoepidemiological study from the Norwegian Prescription Database. Acta Anaesthesiologica Scandinavica. volum 53 (5).
  Academic article

2008

• Fredheim, Olav Magnus; Borchgrevink, Petter; Landmark, Tormod; Schjødt, Borrik; Breivik, Harald. (2008) Et nytt skjema for kartlegging av smerter. Tidsskrift for Den norske legeforening. volum 128 (18).
  Feature article
• Fredheim, Olav Magnus. (2008) Bokanmeldelse av ”Pain management for older adults” (2008) av Hadjistavropoulos T, Hadjistavropoulos HD, red. Tidsskrift for Den norske legeforening. volum 128.
  Book review
• Fredheim, Olav Magnus. (2008) Er vaksiner for dyre? Bokanmeldelse av ”Økonomi på trikken” (2007) av Erling Røed Larsen. Tidsskrift for Den norske legeforening. volum 128.
  Book review
• Fredheim, Olav Magnus. (2008) Health related quality of life assessment and aspects of the clinical pharmacology of methadone in patients with chronic non-malignant pain. Acta Anaesthesiologica Scandinavica. volum 52.
  Abstract
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Breivik, Harald. (2008) Nye begreper knyttet til opioidbehandling. Tidsskrift for Den norske legeforening. volum 128.
  Short communication
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Landmark, Tormod; Schjødt, Borrik; Breivik, Harald. (2008) Et nytt skjema for kartlegging av smerter. Tidsskrift for Den norske legeforening. volum 128 (18).
  Feature article
• Fredheim, Olav Magnus; Kaasa, Stein; Fayers, Peter; Saltnes, Turid; Jordhøy, Marit S; Borchgrevink, Petter Chr.. (2008) Chronic non-malignant pain patients report as poor health-related quality of life as palliative cancer patients. Acta Anaesthesiologica Scandinavica. volum 52 (1).
  Academic article
• Fredheim, Olav Magnus; Moksnes, Kristin; Borchgrevink, Petter Chr.; Kaasa, Stein; Dale, Ola. (2008) Clinical pharmacology of methadone for pain. Acta Anaesthesiologica Scandinavica. volum 52 (7).
  Academic literature review
• Husby, Kristin Moksnes; Fredheim, Olav Magnus; Klepstad, Pål; Kaasa, Stein; Angelsen, Anders; Nilsen, Turid; Dale, Ola. (2008) Early pharmacokinetics of nasal fentanyl: is there a significant arterio-venous difference?. European Journal of Clinical Pharmacology. volum 64 (5).
  Academic article

2007

• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Kaasa, Stein; Dale, Ola; Klepstad, Pål. (2007) Health related quality of life assessment and aspects of the clinical pharmacology of methadone in patients with chronic non-malignant pain. 2007. ISBN 978-82-471-2100-9.
  Doctoral dissertation
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Klepstad, Pål; Kaasa, Stein; Dale, Ola. (2007) Long term methadone for chronic pain: A pilot study of pharmacokinetic aspects. European Journal of Pain. volum 11.
  Academic article
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Saltnes, Turid; Kaasa, Stein. (2007) Validation and Comparison of the Health-Related Quality of Life Instruments EORTC QLQ and SF-36 in Assesment of Patients with Cronic Nonmalignent Pain. Journal of Pain and Symptom Management. volum 34.
  Academic article

2006

• Fredheim, Olav Magnus; Kaasa, Stein; Dale, Ola; Klepstad, Pål; Landrø, Nils Inge; Borchgrevink, Petter C. (2006) Opioid switching from oral slow release morphine to oral methadone may improve pain control in chronic non-malignant pain: a nine-month follow-up study. Palliative Medicine. volum 20.
  Academic article
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Hegrenaes, L; Kaasa, Stein; Dale, Ola; Klepstad, Pål. (2006) Opioid switching from morphine to methadone causes a minor but not clinically significant increase in QTc time: A prospective 9-month follow-up study. Journal of Pain and Symptom Management. volum 32 (2).
  Academic article
• Fredheim, Olav Magnus; Borchgrevink, Petter Chr.; Klepstad, Pål; Kaasa, Stein; Dale, Ola. (2006) Long term methadone for chronic pain: A pilot study of pharmacokinetic aspects. European Journal of Pain.
  Academic article
• Fredheim, Olav Magnus; Husby, Kristin Moksnes; Kaasa, Stein; Borchgrevink, Petter Chr.; Klepstad, Pål. (2006) Opioid switching and methadone in pain relief. Tidsskrift for Den norske legeforening. volum 126.
  Academic article
• Fredheim, Olav Magnus; Husby, Kristin Moksnes; Kaasa, Stein; Borchgrevink, Petter Chr.; Klepstad, Pål. (2006) Opioidrotasjon og metadon i smertebehandling. Tidsskrift for Den norske legeforening. volum 17 (126).
  Academic article
• Fredheim, Olav Magnus; Kaasa, Stein; Dale, Ola; Klepstad, Pål; Landrø, Nils Inge; Borchgrevink, Petter Chr.. (2006) Opioid switching from oral slow release morphine to oral methadone may improve pain control in chronic non-malignant pain: a nine-month follow-up study. Palliative Medicine. volum 20 (1).
  Academic article